fs/proc/proc_sysctl.c: Fix a NULL pointer dereference

Syzkaller report this:

sysctl could not get directory: /net//bridge -12
kasan: CONFIG_KASAN_INLINE enabled
kasan:

fs/proc/proc_sysctl.c: Fix a NULL pointer dereference

Syzkaller report this:

sysctl could not get directory: /net//bridge -12
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN PTI
CPU: 1 PID: 7027 Comm: syz-executor.0 Tainted: G C 5.1.0-rc3+ #8
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:__write_once_size include/linux/compiler.h:220 [inline]
RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:144 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:186 [inline]
RIP: 0010:rb_erase+0x5f4/0x19f0 lib/rbtree.c:459
Code: 00 0f 85 60 13 00 00 48 89 1a 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 75 0c 00 00 4d 85 ed 4c 89 2e 74 ce 4c 89 ea 48
RSP: 0018:ffff8881bb507778 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff8881f224b5b8 RCX: ffffffff818f3f6a
RDX: 000000000000000a RSI: 0000000000000050 RDI: ffff8881f224b568
RBP: 0000000000000000 R08: ffffed10376a0ef4 R09: ffffed10376a0ef4
R10: 0000000000000001 R11: ffffed10376a0ef4 R12: ffff8881f224b558
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f3e7ce13700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd60fbe9398 CR3: 00000001cb55c001 CR4: 00000000007606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
erase_entry fs/proc/proc_sysctl.c:178 [inline]
erase_header+0xe3/0x160 fs/proc/proc_sysctl.c:207
start_unregistering fs/proc/proc_sysctl.c:331 [inline]
drop_sysctl_table+0x558/0x880 fs/proc/proc_sysctl.c:1631
get_subdir fs/proc/proc_sysctl.c:1022 [inline]
__register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335
br_netfilter_init+0x68/0x1000 [br_netfilter]
do_one_initcall+0xbc/0x47d init/main.c:901
do_init_module+0x1b5/0x547 kernel/module.c:3456
load_module+0x6405/0x8c10 kernel/module.c:3804
__do_sys_finit_module+0x162/0x190 kernel/module.c:3898
do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Modules linked in: br_netfilter(+) backlight comedi(C) hid_sensor_hub max3100 ti_ads8688 udc_core fddi snd_mona leds_gpio rc_streamzap mtd pata_netcell nf_log_common rc_winfast udp_tunnel snd_usbmidi_lib snd_usb_toneport snd_usb_line6 snd_rawmidi snd_seq_device snd_hwdep videobuf2_v4l2 videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops rc_gadmei_rm008z 8250_of smm665 hid_tmff hid_saitek hwmon_vid rc_ati_tv_wonder_hd_600 rc_core pata_pdc202xx_old dn_rtmsg as3722 ad714x_i2c ad714x snd_soc_cs4265 hid_kensington panel_ilitek_ili9322 drm drm_panel_orientation_quirks ipack cdc_phonet usbcore phonet hid_jabra hid extcon_arizona can_dev industrialio_triggered_buffer kfifo_buf industrialio adm1031 i2c_mux_ltc4306 i2c_mux ipmi_msghandler mlxsw_core snd_soc_cs35l34 snd_soc_core snd_pcm_dmaengine snd_pcm snd_timer ac97_bus snd_compress snd soundcore gpio_da9055 uio ecdh_generic mdio_thunder of_mdio fixed_phy libphy mdio_cavium iptable_security iptable_raw iptable_mangle
iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel ide_pci_generic piix aes_x86_64 crypto_simd cryptd ide_core glue_helper input_leds psmouse intel_agp intel_gtt serio_raw ata_generic i2c_piix4 agpgart pata_acpi parport_pc parport floppy rtc_cmos sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: br_netfilter]
Dumping ftrace buffer:
(ftrace buffer empty)
---[ end trace 68741688d5fbfe85 ]---

commit 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer
dereference in put_links") forgot to handle start_unregistering() case,
while header->parent is NULL, it calls erase_header() and as seen in the
above syzkaller call trace, accessing &header->parent->root will trigger
a NULL pointer dereference.

As that commit explained, there is also no need to call
start_unregistering() if header->parent is NULL.

Link: http://lkml.kernel.org/r/20190409153622.28112-1-yuehaibing@huawei.com
Fixes: 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links")
Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

bpf: Add file_pos field to bpf_sysctl ctx

Add file_pos field to bpf_sysctl context to read and write sysctl file
position at which sysctl is being accessed (read or written).

Th

bpf: Add file_pos field to bpf_sysctl ctx

Add file_pos field to bpf_sysctl context to read and write sysctl file
position at which sysctl is being accessed (read or written).

The field can be used to e.g. override whole sysctl value on write to
sysctl even when sys_write is called by user space with file_pos > 0. Or
BPF program may reject such accesses.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

bpf: Introduce bpf_sysctl_{get,set}_new_value helpers

Add helpers to work with new value being written to sysctl by user
space.

bpf_sysctl_get_new_value() copies value being wri

bpf: Introduce bpf_sysctl_{get,set}_new_value helpers

Add helpers to work with new value being written to sysctl by user
space.

bpf_sysctl_get_new_value() copies value being written to sysctl into
provided buffer.

bpf_sysctl_set_new_value() overrides new value being written by user
space with a one from provided buffer. Buffer should contain string
representation of the value, similar to what can be seen in /proc/sys/.

Both helpers can be used only on sysctl write.

File position matters and can be managed by an interface that will be
introduced separately. E.g. if user space calls sys_write to a file in
/proc/sys/ at file position = X, where X > 0, then the value set by
bpf_sysctl_set_new_value() will be written starting from X. If program
wants to override whole value with specified buffer, file position has
to be set to zero.

Documentation for the new helpers is provided in bpf.h UAPI.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

bpf: Sysctl hook

Containerized applications may run as root and it may create problems
for whole host. Specifically such applications may change a sysctl and
affect applications in o

bpf: Sysctl hook

Containerized applications may run as root and it may create problems
for whole host. Specifically such applications may change a sysctl and
affect applications in other containers.

Furthermore in existing infrastructure it may not be possible to just
completely disable writing to sysctl, instead such a process should be
gradual with ability to log what sysctl are being changed by a
container, investigate, limit the set of writable sysctl to currently
used ones (so that new ones can not be changed) and eventually reduce
this set to zero.

The patch introduces new program type BPF_PROG_TYPE_CGROUP_SYSCTL and
attach type BPF_CGROUP_SYSCTL to solve these problems on cgroup basis.

New program type has access to following minimal context:
struct bpf_sysctl {
__u32 write;
};

Where @write indicates whether sysctl is being read (= 0) or written (=
1).

Helpers to access sysctl name and value will be introduced separately.

BPF_CGROUP_SYSCTL attach point is added to sysctl code right before
passing control to ctl_table->proc_handler so that BPF program can
either allow or deny access to sysctl.

Suggested-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links

Syzkaller reports:

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault:

fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links

Syzkaller reports:

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN PTI
CPU: 1 PID: 5373 Comm: syz-executor.0 Not tainted 5.0.0-rc8+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:put_links+0x101/0x440 fs/proc/proc_sysctl.c:1599
Code: 00 0f 85 3a 03 00 00 48 8b 43 38 48 89 44 24 20 48 83 c0 38 48 89 c2 48 89 44 24 28 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 fe 02 00 00 48 8b 74 24 20 48 c7 c7 60 2a 9d 91
RSP: 0018:ffff8881d828f238 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881e01b1140 RCX: ffffffff8ee98267
RDX: 0000000000000007 RSI: ffffc90001479000 RDI: ffff8881e01b1178
RBP: dffffc0000000000 R08: ffffed103ee27259 R09: ffffed103ee27259
R10: 0000000000000001 R11: ffffed103ee27258 R12: fffffffffffffff4
R13: 0000000000000006 R14: ffff8881f59838c0 R15: dffffc0000000000
FS: 00007f072254f700(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff8b286668 CR3: 00000001f0542002 CR4: 00000000007606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
drop_sysctl_table+0x152/0x9f0 fs/proc/proc_sysctl.c:1629
get_subdir fs/proc/proc_sysctl.c:1022 [inline]
__register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335
br_netfilter_init+0xbc/0x1000 [br_netfilter]
do_one_initcall+0xfa/0x5ca init/main.c:887
do_init_module+0x204/0x5f6 kernel/module.c:3460
load_module+0x66b2/0x8570 kernel/module.c:3808
__do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462e99
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f072254ec58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000003
RBP: 00007f072254ec70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f072254f6bc
R13: 00000000004bcefa R14: 00000000006f6fb0 R15: 0000000000000004
Modules linked in: br_netfilter(+) dvb_usb_dibusb_mc_common dib3000mc dibx000_common dvb_usb_dibusb_common dvb_usb_dw2102 dvb_usb classmate_laptop palmas_regulator cn videobuf2_v4l2 v4l2_common snd_soc_bd28623 mptbase snd_usb_usx2y snd_usbmidi_lib snd_rawmidi wmi libnvdimm lockd sunrpc grace rc_kworld_pc150u rc_core rtc_da9063 sha1_ssse3 i2c_cros_ec_tunnel adxl34x_spi adxl34x nfnetlink lib80211 i5500_temp dvb_as102 dvb_core videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops udc_core lnbp22 leds_lp3952 hid_roccat_ryos s1d13xxxfb mtd vport_geneve openvswitch nf_conncount nf_nat_ipv6 nsh geneve udp_tunnel ip6_udp_tunnel snd_soc_mt6351 sis_agp phylink snd_soc_adau1761_spi snd_soc_adau1761 snd_soc_adau17x1 snd_soc_core snd_pcm_dmaengine ac97_bus snd_compress snd_soc_adau_utils snd_soc_sigmadsp_regmap snd_soc_sigmadsp raid_class hid_roccat_konepure hid_roccat_common hid_roccat c2port_duramar2150 core mdio_bcm_unimac iptable_security iptable_raw iptable_mangle
iptable_nat nf_nat_ipv4 nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim devlink vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel joydev mousedev ide_pci_generic piix aesni_intel aes_x86_64 ide_core crypto_simd atkbd cryptd glue_helper serio_raw ata_generic pata_acpi i2c_piix4 floppy sch_fq_codel ip_tables x_tables ipv6 [last unloaded: lm73]
Dumping ftrace buffer:
(ftrace buffer empty)
---[ end trace 770020de38961fd0 ]---

A new dir entry can be created in get_subdir and its 'header->parent' is
set to NULL. Only after insert_header success, it will be set to 'dir',
otherwise 'header->parent' is set to NULL and drop_sysctl_table is called.
However in err handling path of get_subdir, drop_sysctl_table also be
called on 'new->header' regardless its value of parent pointer. Then
put_links is called, which triggers NULL-ptr deref when access member of
header->parent.

In fact we have multiple error paths which call drop_sysctl_table() there,
upon failure on insert_links() we also call drop_sysctl_table().And even
in the successful case on __register_sysctl_table() we still always call
drop_sysctl_table().This patch fix it.

Link: http://lkml.kernel.org/r/20190314085527.13244-1-yuehaibing@huawei.com
Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org> [3.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

proc/sysctl: don't return ENOMEM on lookup when a table is unregistering

proc_sys_lookup can fail with ENOMEM instead of ENOENT when the
corresponding sysctl table is being unregistered.

proc/sysctl: don't return ENOMEM on lookup when a table is unregistering

proc_sys_lookup can fail with ENOMEM instead of ENOENT when the
corresponding sysctl table is being unregistered. In our case we see
this upon opening /proc/sys/net/*/conf files while network interfaces
are being deleted, which confuses our configuration daemon.

The problem was successfully reproduced and this fix tested on v4.9.122
and v4.20-rc6.

v2: return ERR_PTRs in all cases when proc_sys_make_inode fails instead
of mixing them with NULL. Thanks Al Viro for the feedback.

Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.")
Cc: stable@vger.kernel.org
Signed-off-by: Ivan Delalande <colona@arista.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

show more ...

treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:

treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

show more ...

switch the rest of procfs lookups to d_splice_alias()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/proc/proc_sysctl.c: fix typo in sysctl_check_table_array()

Patch series "ipc: Clamp *mni to the real IPCMNI limit", v3.

The sysctl parameters msgmni, shmmni and semmni have an in

fs/proc/proc_sysctl.c: fix typo in sysctl_check_table_array()

Patch series "ipc: Clamp *mni to the real IPCMNI limit", v3.

The sysctl parameters msgmni, shmmni and semmni have an inherent limit
of IPC_MNI (32k). However, users may not be aware of that because they
can write a value much higher than that without getting any error or
notification. Reading the parameters back will show the newly written
values which are not real.

Enforcing the limit by failing sysctl parameter write, however, can
break existing user applications. To address this delemma, a new flags
field is introduced into the ctl_table. The value CTL_FLAGS_CLAMP_RANGE
can be added to any ctl_table entries to enable a looser range clamping
without returning any error. For example,

.flags = CTL_FLAGS_CLAMP_RANGE,

This flags value are now used for the range checking of shmmni, msgmni
and semmni without breaking existing applications. If any out of range
value is written to those sysctl parameters, the following warning will
be printed instead.

Kernel parameter "shmmni" was set out of range [0, 32768], clamped to 32768.

Reading the values back will show 32768 instead of some fake values.

This patch (of 6):

Fix a typo.

Link: http://lkml.kernel.org/r/1519926220-7453-2-git-send-email-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

fs/proc/proc_sysctl.c: remove redundant link check in proc_sys_link_fill_cache()

proc_sys_link_fill_cache() does not need to check whether we're called
for a link - it's already done by

fs/proc/proc_sysctl.c: remove redundant link check in proc_sys_link_fill_cache()

proc_sys_link_fill_cache() does not need to check whether we're called
for a link - it's already done by scan().

Link: http://lkml.kernel.org/r/20180228013506.4915-2-danilokrummrich@dk-develop.de
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

fs/proc/proc_sysctl.c: fix potential page fault while unregistering sysctl table

proc_sys_link_fill_cache() does not take currently unregistering sysctl
tables into account, which might

fs/proc/proc_sysctl.c: fix potential page fault while unregistering sysctl table

proc_sys_link_fill_cache() does not take currently unregistering sysctl
tables into account, which might result into a page fault in
sysctl_follow_link() - add a check to fix it.

This bug has been present since v3.4.

Link: http://lkml.kernel.org/r/20180228013506.4915-1-danilokrummrich@dk-develop.de
Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets")
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

vfs: do bulk POLL* -> EPOLL* replacement

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

for V in IN OUT

vfs: do bulk POLL* -> EPOLL* replacement

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

fs: annotate ->poll() instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:

- various misc things

- kexec updates

- sysctl core updates

- scripts

Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:

- various misc things

- kexec updates

- sysctl core updates

- scripts/gdb udpates

- checkpoint-restart updates

- ipc updates

- kernel/watchdog updates

- Kees's "rough equivalent to the glibc _FORTIFY_SOURCE=1 feature"

- "stackprotector: ascii armor the stack canary"

- more MM bits

- checkpatch updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits)
writeback: rework wb_[dec|inc]_stat family of functions
ARM: samsung: usb-ohci: move inline before return type
video: fbdev: omap: move inline before return type
video: fbdev: intelfb: move inline before return type
USB: serial: safe_serial: move __inline__ before return type
drivers: tty: serial: move inline before return type
drivers: s390: move static and inline before return type
x86/efi: move asmlinkage before return type
sh: move inline before return type
MIPS: SMP: move asmlinkage before return type
m68k: coldfire: move inline before return type
ia64: sn: pci: move inline before type
ia64: move inline before return type
FRV: tlbflush: move asmlinkage before return type
CRIS: gpio: move inline before return type
ARM: HP Jornada 7XX: move inline before return type
ARM: KVM: move asmlinkage before type
checkpatch: improve the STORAGE_CLASS test
mm, migration: do not trigger OOM killer when migrating memory
drm/i915: use __GFP_RETRY_MAYFAIL
...

show more ...

sysctl: add unsigned int range support

To keep parity with regular int interfaces provide the an unsigned int
proc_douintvec_minmax() which allows you to specify a range of allowed
v

sysctl: add unsigned int range support

To keep parity with regular int interfaces provide the an unsigned int
proc_douintvec_minmax() which allows you to specify a range of allowed
valid numbers.

Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an
actual user for that.

Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

sysctl: simplify unsigned int support

Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32
fields") added proc_douintvec() to start help adding support for
unsigned int

sysctl: simplify unsigned int support

Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32
fields") added proc_douintvec() to start help adding support for
unsigned int, this however was only half the work needed. Two fixes
have come in since then for the following issues:

o Printing the values shows a negative value, this happens since
do_proc_dointvec() and this uses proc_put_long()

This was fixed by commit 5380e5644afbba9 ("sysctl: don't print negative
flag for proc_douintvec").

o We can easily wrap around the int values: UINT_MAX is 4294967295, if
we echo in 4294967295 + 1 we end up with 0, using 4294967295 + 2 we
end up with 1.
o We echo negative values in and they are accepted

This was fixed by commit 425fffd886ba ("sysctl: report EINVAL if value
is larger than UINT_MAX for proc_douintvec").

It still also failed to be added to sysctl_check_table()... instead of
adding it with the current implementation just provide a proper and
simplified unsigned int support without any array unsigned int support
with no negative support at all.

Historically sysctl proc helpers have supported arrays, due to the
complexity this adds though we've taken a step back to evaluate array
users to determine if its worth upkeeping for unsigned int. An
evaluation using Coccinelle has been done to perform a grammatical
search to ask ourselves:

o How many sysctl proc_dointvec() (int) users exist which likely
should be moved over to proc_douintvec() (unsigned int) ?
Answer: about 8
- Of these how many are array users ?
Answer: Probably only 1
o How many sysctl array users exist ?
Answer: about 12

This last question gives us an idea just how popular arrays: they are not.
Array support should probably just be kept for strings.

The identified uint ports are:

drivers/infiniband/core/ucma.c - max_backlog
drivers/infiniband/core/iwcm.c - default_backlog
net/core/sysctl_net_core.c - rps_sock_flow_sysctl()
net/netfilter/nf_conntrack_timestamp.c - nf_conntrack_timestamp -- bool
net/netfilter/nf_conntrack_acct.c nf_conntrack_acct -- bool
net/netfilter/nf_conntrack_ecache.c - nf_conntrack_events -- bool
net/netfilter/nf_conntrack_helper.c - nf_conntrack_helper -- bool
net/phonet/sysctl.c proc_local_port_range()

The only possible array users is proc_local_port_range() but it does not
seem worth it to add array support just for this given the range support
works just as well. Unsigned int support should be desirable more for
when you *need* more than INT_MAX or using int min/max support then does
not suffice for your ranges.

If you forget and by mistake happen to register an unsigned int proc
entry with an array, the driver will fail and you will get something as
follows:

sysctl table check failed: debug/test_sysctl//uint_0002 array now allowed
CPU: 2 PID: 1342 Comm: modprobe Tainted: G W E <etc>
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS <etc>
Call Trace:
dump_stack+0x63/0x81
__register_sysctl_table+0x350/0x650
? kmem_cache_alloc_trace+0x107/0x240
__register_sysctl_paths+0x1b3/0x1e0
? 0xffffffffc005f000
register_sysctl_table+0x1f/0x30
test_sysctl_init+0x10/0x1000 [test_sysctl]
do_one_initcall+0x52/0x1a0
? kmem_cache_alloc_trace+0x107/0x240
do_init_module+0x5f/0x200
load_module+0x1867/0x1bd0
? __symbol_put+0x60/0x60
SYSC_finit_module+0xdf/0x110
SyS_finit_module+0xe/0x10
entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f042b22d119
<etc>

Fixes: e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields")
Link: http://lkml.kernel.org/r/20170519033554.18592-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Liping Zhang <zlpnobody@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

sysctl: fix lax sysctl_check_table() sanity check

Patch series "sysctl: few fixes", v5.

I've been working on making kmod more deterministic, and as I did that I
couldn't help bu

sysctl: fix lax sysctl_check_table() sanity check

Patch series "sysctl: few fixes", v5.

I've been working on making kmod more deterministic, and as I did that I
couldn't help but notice a few issues with sysctl. My end goal was just
to fix unsigned int support, which back then was completely broken.
Liping Zhang has sent up small atomic fixes, however it still missed yet
one more fix and Alexey Dobriyan had also suggested to just drop array
support given its complexity.

I have inspected array support using Coccinelle and indeed its not that
popular, so if in fact we can avoid it for new interfaces, I agree its
best.

I did develop a sysctl stress driver but will hold that off for another
series.

This patch (of 5):

Commit 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks")
improved sanity checks considerbly, however the enhancements on
sysctl_check_table() meant adding a functional change so that only the
last table entry's sanity error is propagated. It also changed the way
errors were propagated so that each new check reset the err value, this
means only last sanity check computed is used for an error. This has
been in the kernel since v3.4 days.

Fix this by carrying on errors from previous checks and iterations as we
traverse the table and ensuring we keep any error from previous checks.
We keep iterating on the table even if an error is found so we can
complain for all errors found in one shot. This works as -EINVAL is
always returned on error anyway, and the check for error is any non-zero
value.

Fixes: 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks")
Link: http://lkml.kernel.org/r/20170519033554.18592-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

proc: Fix proc_sys_prune_dcache to hold a sb reference

Andrei Vagin writes:
FYI: This bug has been reproduced on 4.11.7
> BUG: Dentry ffff895a3dd01240{i=4e7c09a,n=lo} still in use (

proc: Fix proc_sys_prune_dcache to hold a sb reference

Andrei Vagin writes:
FYI: This bug has been reproduced on 4.11.7
> BUG: Dentry ffff895a3dd01240{i=4e7c09a,n=lo} still in use (1) [unmount of proc proc]
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 13588 at fs/dcache.c:1445 umount_check+0x6e/0x80
> CPU: 1 PID: 13588 Comm: kworker/1:1 Not tainted 4.11.7-200.fc25.x86_64 #1
> Hardware name: CompuLab sbc-flt1/fitlet, BIOS SBCFLT_0.08.04 06/27/2015
> Workqueue: events proc_cleanup_work
> Call Trace:
> dump_stack+0x63/0x86
> __warn+0xcb/0xf0
> warn_slowpath_null+0x1d/0x20
> umount_check+0x6e/0x80
> d_walk+0xc6/0x270
> ? dentry_free+0x80/0x80
> do_one_tree+0x26/0x40
> shrink_dcache_for_umount+0x2d/0x90
> generic_shutdown_super+0x1f/0xf0
> kill_anon_super+0x12/0x20
> proc_kill_sb+0x40/0x50
> deactivate_locked_super+0x43/0x70
> deactivate_super+0x5a/0x60
> cleanup_mnt+0x3f/0x90
> mntput_no_expire+0x13b/0x190
> kern_unmount+0x3e/0x50
> pid_ns_release_proc+0x15/0x20
> proc_cleanup_work+0x15/0x20
> process_one_work+0x197/0x450
> worker_thread+0x4e/0x4a0
> kthread+0x109/0x140
> ? process_one_work+0x450/0x450
> ? kthread_park+0x90/0x90
> ret_from_fork+0x2c/0x40
> ---[ end trace e1c109611e5d0b41 ]---
> VFS: Busy inodes after unmount of proc. Self-destruct in 5 seconds. Have a nice day...
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: _raw_spin_lock+0xc/0x30
> PGD 0

Fix this by taking a reference to the super block in proc_sys_prune_dcache.

The superblock reference is the core of the fix however the sysctl_inodes
list is converted to a hlist so that hlist_del_init_rcu may be used. This
allows proc_sys_prune_dache to remove inodes the sysctl_inodes list, while
not causing problems for proc_sys_evict_inode when if it later choses to
remove the inode from the sysctl_inodes list. Removing inodes from the
sysctl_inodes list allows proc_sys_prune_dcache to have a progress
guarantee, while still being able to drop all locks. The fact that
head->unregistering is set in start_unregistering ensures that no more
inodes will be added to the the sysctl_inodes list.

Previously the code did a dance where it delayed calling iput until the
next entry in the list was being considered to ensure the inode remained on
the sysctl_inodes list until the next entry was walked to. The structure
of the loop in this patch does not need that so is much easier to
understand and maintain.

Cc: stable@vger.kernel.org
Reported-by: Andrei Vagin <avagin@gmail.com>
Tested-by: Andrei Vagin <avagin@openvz.org>
Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.")
Fixes: d6cffbbe9a7e ("proc/sysctl: prune stale dentries during unregistering")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

show more ...

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull namespace updates from Eric Biederman:
"This is a set of small fixes that were mos

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull namespace updates from Eric Biederman:
"This is a set of small fixes that were mostly stumbled over during
more significant development. This proc fix and the fix to
posix-timers are the most significant of the lot.

There is a lot of good development going on but unfortunately it
didn't quite make the merge window"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc: Fix unbalanced hard link numbers
signal: Make kill_proc_info static
rlimit: Properly call security_task_setrlimit
signal: Remove unused definition of sig_user_definied
ia64: Remove unused IA64_TASK_SIGHAND_OFFSET and IA64_SIGHAND_SIGLOCK_OFFSET
ipc: Remove unused declaration of recompute_msgmni
posix-timers: Correct sanity check in posix_cpu_nsleep
sysctl: Remove dead register_sysctl_root

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sysctl: Remove dead register_sysctl_root

The function no longer does anything. The is only a single caller of
register_sysctl_root when semantically there should be two. Remove
thi

sysctl: Remove dead register_sysctl_root

The function no longer does anything. The is only a single caller of
register_sysctl_root when semantically there should be two. Remove
this function so that if someone decides this functionality is needed
again it will be obvious all of the callers of setup_sysctl_set need
to be audited and modified appropriately.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

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sysctl: add sanity check for proc_douintvec

Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32
fields") introduced the proc_douintvec helper function, but it forgot to

sysctl: add sanity check for proc_douintvec

Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32
fields") introduced the proc_douintvec helper function, but it forgot to
add the related sanity check when doing register_sysctl_table. So add
it now.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs 'statx()' update from Al Viro.

This adds the new extended stat() interface that inter

Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs 'statx()' update from Al Viro.

This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.

It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?

From David Howells.

Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:

https://www.spinics.net/lists/linux-fsdevel/msg33831.html

* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
statx: Add a system call to make enhanced file info available

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statx: Add a system call to make enhanced file info available

Add a system call to make extended file information available, including
file creation and some attribute flags where availa

statx: Add a system call to make enhanced file info available

Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included. The
following have been included:

(1) Make the fields a consistent size on all arches and make them large.

(2) Spare space, request flags and information flags are provided for
future expansion.

(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).

(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).

This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].

(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).

(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].

Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.

(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).

(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].

(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].

(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...

(This requires a separate system call - I have an fsinfo() call idea
for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].

(Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].

(Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).

(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].

(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.

(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.

(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data. This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};

struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};

The defined bits in request_mask and stx_mask are:

STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:

STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

STATX_ATTR_AUTOMOUNT Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

(0) stx_dev_*, stx_blksize.

These are local system information and are always available.

(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.

These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.

If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.

If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.

Note that there are instances where the type might not be valid, for
instance Windows reparse points.

(2) stx_rdev_*.

This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.

(3) stx_btime.

Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>

Add #include <linux/cred.h> dependencies to all .c files rely on sched.h
doing that for them.

Note

sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>

Add #include <linux/cred.h> dependencies to all .c files rely on sched.h
doing that for them.

Note that even if the count where we need to add extra headers seems high,
it's still a net win, because <linux/sched.h> is included in over
2,200 files ...

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...