#
2fd1d2c4 |
| 06-Jul-2017 |
Eric W. Biederman <ebiederm@xmission.com> |
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 p
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>
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Revision tags: v4.12, v4.10.17, v4.10.16, v4.10.15, v4.10.14, v4.10.13, v4.10.12, v4.10.11, v4.10.10, v4.10.9, v4.10.8, v4.10.7, v4.10.6 |
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#
b54807fa |
| 24-Mar-2017 |
Eric W. Biederman <ebiederm@xmission.com> |
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 th
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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#
1680a386 |
| 07-Apr-2017 |
Liping Zhang <zlpnobody@gmail.com> |
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 relate
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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Revision tags: v4.10.5, v4.10.4, v4.10.3, v4.10.2, v4.10.1, v4.10 |
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#
a528d35e |
| 31-Jan-2017 |
David Howells <dhowells@redhat.com> |
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
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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#
5b825c3a |
| 02-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
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 co
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>
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#
ace0c791 |
| 19-Feb-2017 |
Eric W. Biederman <ebiederm@xmission.com> |
proc/sysctl: Don't grab i_lock under sysctl_lock.
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> writes: > This patch has locking problem. I've got lockdep splat under LTP. > > [ 6633.115456] ===
proc/sysctl: Don't grab i_lock under sysctl_lock.
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> writes: > This patch has locking problem. I've got lockdep splat under LTP. > > [ 6633.115456] ====================================================== > [ 6633.115502] [ INFO: possible circular locking dependency detected ] > [ 6633.115553] 4.9.10-debug+ #9 Tainted: G L > [ 6633.115584] ------------------------------------------------------- > [ 6633.115627] ksm02/284980 is trying to acquire lock: > [ 6633.115659] (&sb->s_type->i_lock_key#4){+.+...}, at: [<ffffffff816bc1ce>] igrab+0x1e/0x80 > [ 6633.115834] but task is already holding lock: > [ 6633.115882] (sysctl_lock){+.+...}, at: [<ffffffff817e379b>] unregister_sysctl_table+0x6b/0x110 > [ 6633.116026] which lock already depends on the new lock. > [ 6633.116026] > [ 6633.116080] > [ 6633.116080] the existing dependency chain (in reverse order) is: > [ 6633.116117] > -> #2 (sysctl_lock){+.+...}: > -> #1 (&(&dentry->d_lockref.lock)->rlock){+.+...}: > -> #0 (&sb->s_type->i_lock_key#4){+.+...}: > > d_lock nests inside i_lock > sysctl_lock nests inside d_lock in d_compare > > This patch adds i_lock nesting inside sysctl_lock.
Al Viro <viro@ZenIV.linux.org.uk> replied: > Once ->unregistering is set, you can drop sysctl_lock just fine. So I'd > try something like this - use rcu_read_lock() in proc_sys_prune_dcache(), > drop sysctl_lock() before it and regain after. Make sure that no inodes > are added to the list ones ->unregistering has been set and use RCU list > primitives for modifying the inode list, with sysctl_lock still used to > serialize its modifications. > > Freeing struct inode is RCU-delayed (see proc_destroy_inode()), so doing > igrab() is safe there. Since we don't drop inode reference until after we'd > passed beyond it in the list, list_for_each_entry_rcu() should be fine.
I agree with Al Viro's analsysis of the situtation.
Fixes: d6cffbbe9a7e ("proc/sysctl: prune stale dentries during unregistering") Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Tested-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
d6cffbbe |
| 10-Feb-2017 |
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> |
proc/sysctl: prune stale dentries during unregistering
Currently unregistering sysctl table does not prune its dentries. Stale dentries could slowdown sysctl operations significantly.
For example,
proc/sysctl: prune stale dentries during unregistering
Currently unregistering sysctl table does not prune its dentries. Stale dentries could slowdown sysctl operations significantly.
For example, command:
# for i in {1..100000} ; do unshare -n -- sysctl -a &> /dev/null ; done creates a millions of stale denties around sysctls of loopback interface:
# sysctl fs.dentry-state fs.dentry-state = 25812579 24724135 45 0 0 0
All of them have matching names thus lookup have to scan though whole hash chain and call d_compare (proc_sys_compare) which checks them under system-wide spinlock (sysctl_lock).
# time sysctl -a > /dev/null real 1m12.806s user 0m0.016s sys 1m12.400s
Currently only memory reclaimer could remove this garbage. But without significant memory pressure this never happens.
This patch collects sysctl inodes into list on sysctl table header and prunes all their dentries once that table unregisters.
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> writes: > On 10.02.2017 10:47, Al Viro wrote: >> how about >> the matching stats *after* that patch? > > dcache size doesn't grow endlessly, so stats are fine > > # sysctl fs.dentry-state > fs.dentry-state = 92712 58376 45 0 0 0 > > # time sysctl -a &>/dev/null > > real 0m0.013s > user 0m0.004s > sys 0m0.008s
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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#
93362fa4 |
| 05-Jan-2017 |
Zhou Chengming <zhouchengming1@huawei.com> |
sysctl: Drop reference added by grab_header in proc_sys_readdir
Fixes CVE-2016-9191, proc_sys_readdir doesn't drop reference added by grab_header when return from !dir_emit_dots path. It can cause a
sysctl: Drop reference added by grab_header in proc_sys_readdir
Fixes CVE-2016-9191, proc_sys_readdir doesn't drop reference added by grab_header when return from !dir_emit_dots path. It can cause any path called unregister_sysctl_table will wait forever.
The calltrace of CVE-2016-9191:
[ 5535.960522] Call Trace: [ 5535.963265] [<ffffffff817cdaaf>] schedule+0x3f/0xa0 [ 5535.968817] [<ffffffff817d33fb>] schedule_timeout+0x3db/0x6f0 [ 5535.975346] [<ffffffff817cf055>] ? wait_for_completion+0x45/0x130 [ 5535.982256] [<ffffffff817cf0d3>] wait_for_completion+0xc3/0x130 [ 5535.988972] [<ffffffff810d1fd0>] ? wake_up_q+0x80/0x80 [ 5535.994804] [<ffffffff8130de64>] drop_sysctl_table+0xc4/0xe0 [ 5536.001227] [<ffffffff8130de17>] drop_sysctl_table+0x77/0xe0 [ 5536.007648] [<ffffffff8130decd>] unregister_sysctl_table+0x4d/0xa0 [ 5536.014654] [<ffffffff8130deff>] unregister_sysctl_table+0x7f/0xa0 [ 5536.021657] [<ffffffff810f57f5>] unregister_sched_domain_sysctl+0x15/0x40 [ 5536.029344] [<ffffffff810d7704>] partition_sched_domains+0x44/0x450 [ 5536.036447] [<ffffffff817d0761>] ? __mutex_unlock_slowpath+0x111/0x1f0 [ 5536.043844] [<ffffffff81167684>] rebuild_sched_domains_locked+0x64/0xb0 [ 5536.051336] [<ffffffff8116789d>] update_flag+0x11d/0x210 [ 5536.057373] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450 [ 5536.064186] [<ffffffff81167acb>] ? cpuset_css_offline+0x1b/0x60 [ 5536.070899] [<ffffffff810fce3d>] ? trace_hardirqs_on+0xd/0x10 [ 5536.077420] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450 [ 5536.084234] [<ffffffff8115a9f5>] ? css_killed_work_fn+0x25/0x220 [ 5536.091049] [<ffffffff81167ae5>] cpuset_css_offline+0x35/0x60 [ 5536.097571] [<ffffffff8115aa2c>] css_killed_work_fn+0x5c/0x220 [ 5536.104207] [<ffffffff810bc83f>] process_one_work+0x1df/0x710 [ 5536.110736] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710 [ 5536.117461] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0 [ 5536.123697] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710 [ 5536.130426] [<ffffffff810c3f7e>] kthread+0xfe/0x120 [ 5536.135991] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40 [ 5536.142041] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230
One cgroup maintainer mentioned that "cgroup is trying to offline a cpuset css, which takes place under cgroup_mutex. The offlining ends up trying to drain active usages of a sysctl table which apprently is not happening." The real reason is that proc_sys_readdir doesn't drop reference added by grab_header when return from !dir_emit_dots path. So this cpuset offline path will wait here forever.
See here for details: http://www.openwall.com/lists/oss-security/2016/11/04/13
Fixes: f0c3b5093add ("[readdir] convert procfs") Cc: stable@vger.kernel.org Reported-by: CAI Qian <caiqian@redhat.com> Tested-by: Yang Shukui <yangshukui@huawei.com> Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Revision tags: v4.9, openbmc-4.4-20161121-1, v4.4.33, v4.4.32, v4.4.31, v4.4.30, v4.4.29, v4.4.28, v4.4.27, v4.7.10, openbmc-4.4-20161021-1, v4.7.9, v4.4.26, v4.7.8, v4.4.25, v4.4.24, v4.7.7, v4.8, v4.4.23, v4.7.6, v4.7.5, v4.4.22, v4.4.21, v4.7.4 |
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078cd827 |
| 14-Sep-2016 |
Deepa Dinamani <deepa.kernel@gmail.com> |
fs: Replace CURRENT_TIME with current_time() for inode timestamps
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current
fs: Replace CURRENT_TIME with current_time() for inode timestamps
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead.
CURRENT_TIME is also not y2038 safe.
This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe.
Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Revision tags: v4.7.3, v4.4.20, v4.7.2, v4.4.19, openbmc-4.4-20160819-1, v4.7.1, v4.4.18, v4.4.17, openbmc-4.4-20160804-1, v4.4.16, v4.7, openbmc-4.4-20160722-1, openbmc-20160722-1, openbmc-20160713-1, v4.4.15, v4.6.4, v4.6.3, v4.4.14, v4.6.2, v4.4.13, openbmc-20160606-1, v4.6.1, v4.4.12 |
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31051c85 |
| 26-May-2016 |
Jan Kara <jack@suse.cz> |
fs: Give dentry to inode_change_ok() instead of inode
inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument
fs: Give dentry to inode_change_ok() instead of inode
inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
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e79c6a4f |
| 10-Aug-2016 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
net: make net namespace sysctls belong to container's owner
If net namespace is attached to a user namespace let's make container's root owner of sysctls affecting said network namespace instead of
net: make net namespace sysctls belong to container's owner
If net namespace is attached to a user namespace let's make container's root owner of sysctls affecting said network namespace instead of global root.
This also allows us to clean up net_ctl_permissions() because we do not need to fudge permissions anymore for the container's owner since it now owns the objects in question.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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13bcc6a2 |
| 16-Jul-2016 |
Eric W. Biederman <ebiederm@xmission.com> |
sysctl: Stop implicitly passing current into sysctl_table_root.lookup
Passing nsproxy into sysctl_table_root.lookup was a premature optimization in attempt to avoid depending on current. The direct
sysctl: Stop implicitly passing current into sysctl_table_root.lookup
Passing nsproxy into sysctl_table_root.lookup was a premature optimization in attempt to avoid depending on current. The directory /proc/self/sys has not appeared and if and when it does this code will need to be reviewed closely and reworked anyway. So remove the premature optimization.
Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
6fa67e70 |
| 31-Jul-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
get rid of 'parent' argument of ->d_compare()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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dc12e909 |
| 20-Jul-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
qstr: constify instances in procfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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8387ff25 |
| 10-Jun-2016 |
Linus Torvalds <torvalds@linux-foundation.org> |
vfs: make the string hashes salt the hash
We always mixed in the parent pointer into the dentry name hash, but we did it late at lookup time. It turns out that we can simplify that lookup-time acti
vfs: make the string hashes salt the hash
We always mixed in the parent pointer into the dentry name hash, but we did it late at lookup time. It turns out that we can simplify that lookup-time action by salting the hash with the parent pointer early instead of late.
A few other users of our string hashes also wanted to mix in their own pointers into the hash, and those are updated to use the same mechanism.
Hash users that don't have any particular initial salt can just use the NULL pointer as a no-salt.
Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revision tags: openbmc-20160521-1, v4.4.11, openbmc-20160518-1, v4.6, v4.4.10, openbmc-20160511-1, openbmc-20160505-1, v4.4.9 |
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f50752ea |
| 20-Apr-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
switch all procfs directories ->iterate_shared()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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76aab3ab |
| 20-Apr-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
proc_sys_fill_cache(): switch to d_alloc_parallel()
make it usable with directory locked shared
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Revision tags: v4.4.8, v4.4.7, openbmc-20160329-2, openbmc-20160329-1, openbmc-20160321-1, v4.4.6, v4.5, v4.4.5, v4.4.4, v4.4.3, openbmc-20160222-1, v4.4.2, openbmc-20160212-1, openbmc-20160210-1, openbmc-20160202-2, openbmc-20160202-1, v4.4.1, openbmc-20160127-1, openbmc-20160120-1, v4.4, openbmc-20151217-1, openbmc-20151210-1, openbmc-20151202-1, openbmc-20151123-1, openbmc-20151118-1, openbmc-20151104-1, v4.3, openbmc-20151102-1, openbmc-20151028-1, v4.3-rc1, v4.2, v4.2-rc8, v4.2-rc7 |
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a1c83681 |
| 12-Aug-2015 |
Viresh Kumar <viresh.kumar@linaro.org> |
fs: Drop unlikely before IS_ERR(_OR_NULL)
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it.
Signed-off-by: Viresh Kumar <
fs: Drop unlikely before IS_ERR(_OR_NULL)
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Jeff Layton <jlayton@poochiereds.net> Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve French <smfrench@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Revision tags: v4.2-rc6, v4.2-rc5, v4.2-rc4, v4.2-rc3, v4.2-rc2, v4.2-rc1, v4.1, v4.1-rc8, v4.1-rc7, v4.1-rc6, v4.1-rc5, v4.1-rc4, v4.1-rc3 |
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f9bd6733 |
| 09-May-2015 |
Eric W. Biederman <ebiederm@xmission.com> |
sysctl: Allow creating permanently empty directories that serve as mountpoints.
Add a magic sysctl table sysctl_mount_point that when used to create a directory forces that directory to be permanent
sysctl: Allow creating permanently empty directories that serve as mountpoints.
Add a magic sysctl table sysctl_mount_point that when used to create a directory forces that directory to be permanently empty.
Update the code to use make_empty_dir_inode when accessing permanently empty directories.
Update the code to not allow adding to permanently empty directories.
Update /proc/sys/fs/binfmt_misc to be a permanently empty directory.
Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Revision tags: v4.1-rc2, v4.1-rc1, v4.0, v4.0-rc7, v4.0-rc6, v4.0-rc5 |
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2b0143b5 |
| 17-Mar-2015 |
David Howells <dhowells@redhat.com> |
VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by:
VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Revision tags: v4.0-rc4, v4.0-rc3, v4.0-rc2, v4.0-rc1, v3.19, v3.19-rc7, v3.19-rc6, v3.19-rc5, v3.19-rc4, v3.19-rc3, v3.19-rc2, v3.19-rc1, v3.18, v3.18-rc7, v3.18-rc6, v3.18-rc5, v3.18-rc4, v3.18-rc3, v3.18-rc2, v3.18-rc1, v3.17, v3.17-rc7, v3.17-rc6, v3.17-rc5, v3.17-rc4, v3.17-rc3, v3.17-rc2, v3.17-rc1 |
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e5eea098 |
| 08-Aug-2014 |
Joe Perches <joe@perches.com> |
sysctl: remove typedef ctl_table
Remove the final user, and the typedef itself.
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
sysctl: remove typedef ctl_table
Remove the final user, and the typedef itself.
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revision tags: v3.16, v3.16-rc7, v3.16-rc6, v3.16-rc5, v3.16-rc4, v3.16-rc3, v3.16-rc2, v3.16-rc1, v3.15, v3.15-rc8, v3.15-rc7, v3.15-rc6, v3.15-rc5, v3.15-rc4, v3.15-rc3, v3.15-rc2, v3.15-rc1, v3.14, v3.14-rc8, v3.14-rc7, v3.14-rc6, v3.14-rc5, v3.14-rc4, v3.14-rc3, v3.14-rc2, v3.14-rc1, v3.13, v3.13-rc8, v3.13-rc7, v3.13-rc6, v3.13-rc5, v3.13-rc4, v3.13-rc3, v3.13-rc2, v3.13-rc1, v3.12, v3.12-rc7, v3.12-rc6, v3.12-rc5, v3.12-rc4, v3.12-rc3, v3.12-rc2, v3.12-rc1, v3.11, v3.11-rc7, v3.11-rc6, v3.11-rc5, v3.11-rc4, v3.11-rc3, v3.11-rc2, v3.11-rc1, v3.10, v3.10-rc7, v3.10-rc6, v3.10-rc5, v3.10-rc4, v3.10-rc3 |
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#
da53be12 |
| 21-May-2013 |
Linus Torvalds <torvalds@linux-foundation.org> |
Don't pass inode to ->d_hash() and ->d_compare()
Instances either don't look at it at all (the majority of cases) or only want it to find the superblock (which can be had as dentry->d_sb). A few cas
Don't pass inode to ->d_hash() and ->d_compare()
Instances either don't look at it at all (the majority of cases) or only want it to find the superblock (which can be had as dentry->d_sb). A few cases that want more are actually safe with dentry->d_inode - the only precaution needed is the check that it hadn't been replaced with NULL by rmdir() or by overwriting rename(), which case should be simply treated as cache miss.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Revision tags: v3.10-rc2 |
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f0c3b509 |
| 16-May-2013 |
Al Viro <viro@zeniv.linux.org.uk> |
[readdir] convert procfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Revision tags: v3.10-rc1, v3.9, v3.9-rc8, v3.9-rc7, v3.9-rc6, v3.9-rc5, v3.9-rc4, v3.9-rc3, v3.9-rc2, v3.9-rc1 |
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87ebdc00 |
| 27-Feb-2013 |
Andrew Morton <akpm@linux-foundation.org> |
fs/proc: clean up printks
- use pr_foo() throughout
- remove a couple of duplicated KERN_WARNINGs, via WARN(KERN_WARNING "...")
- nuke a few warnings which I've never seen happen, ever.
Cc: Joe P
fs/proc: clean up printks
- use pr_foo() throughout
- remove a couple of duplicated KERN_WARNINGs, via WARN(KERN_WARNING "...")
- nuke a few warnings which I've never seen happen, ever.
Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revision tags: v3.8, v3.8-rc7, v3.8-rc6, v3.8-rc5 |
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496ad9aa |
| 23-Jan-2013 |
Al Viro <viro@zeniv.linux.org.uk> |
new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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