| e80eb1dc | 25-Jun-2020 |
Eric W. Biederman <ebiederm@xmission.com> |
bpfilter: Take advantage of the facilities of struct pid
Instead of relying on the exit_umh cleanup callback use the fact a
struct pid can be tested to see if a process still exists, and that
struct
bpfilter: Take advantage of the facilities of struct pid
Instead of relying on the exit_umh cleanup callback use the fact a
struct pid can be tested to see if a process still exists, and that
struct pid has a wait queue that notifies when the process dies.
v1: https://lkml.kernel.org/r/87h7uydlu9.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/874kqt4owu.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-14-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
show more ...
|
| 1c340ead | 25-Jun-2020 |
Eric W. Biederman <ebiederm@xmission.com> |
umd: Track user space drivers with struct pid
Use struct pid instead of user space pid values that are prone to wrap
araound.
In addition track the entire thread group instead of just the first
thr
umd: Track user space drivers with struct pid
Use struct pid instead of user space pid values that are prone to wrap
araound.
In addition track the entire thread group instead of just the first
thread that is started by exec. There are no multi-threaded user mode
drivers today but there is nothing preclucing user drivers from being
multi-threaded, so it is just a good idea to track the entire process.
Take a reference count on the tgid's in question to make it possible
to remove exit_umh in a future change.
As a struct pid is available directly use kill_pid_info.
The prior process signalling code was iffy in using a userspace pid
known to be in the initial pid namespace and then looking up it's task
in whatever the current pid namespace is. It worked only because
kernel threads always run in the initial pid namespace.
As the tgid is now refcounted verify the tgid is NULL at the start of
fork_usermode_driver to avoid the possibility of silent pid leaks.
v1: https://lkml.kernel.org/r/87mu4qdlv2.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/a70l4oy8.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-12-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
show more ...
|
| 1199c6c3 | 25-Jun-2020 |
Eric W. Biederman <ebiederm@xmission.com> |
umd: Rename umd_info.cmdline umd_info.driver_name
The only thing supplied in the cmdline today is the driver name so
rename the field to clarify the code.
As this value is always supplied stop tryi
umd: Rename umd_info.cmdline umd_info.driver_name
The only thing supplied in the cmdline today is the driver name so
rename the field to clarify the code.
As this value is always supplied stop trying to handle the case of
a NULL cmdline.
Additionally since we now have a name we can count on use the
driver_name any place where the code is looking for a name
of the binary.
v1: https://lkml.kernel.org/r/87imfef0k3.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87366d63os.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-7-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
show more ...
|
| 71a85084 | 08-Jan-2019 |
Taehee Yoo <ap420073@gmail.com> |
net: bpfilter: disallow to remove bpfilter module while being used
The bpfilter.ko module can be removed while functions of the bpfilter.ko
are executing. so panic can occurred. in order to protect
net: bpfilter: disallow to remove bpfilter module while being used
The bpfilter.ko module can be removed while functions of the bpfilter.ko
are executing. so panic can occurred. in order to protect that, locks can
be used. a bpfilter_lock protects routines in the
__bpfilter_process_sockopt() but it's not enough because __exit routine
can be executed concurrently.
Now, the bpfilter_umh can not run in parallel.
So, the module do not removed while it's being used and it do not
double-create UMH process.
The members of the umh_info and the bpfilter_umh_ops are protected by
the bpfilter_umh_ops.lock.
test commands:
while :
do
iptables -I FORWARD -m string --string ap --algo kmp &
modprobe -rv bpfilter &
done
splat looks like:
[ 298.623435] BUG: unable to handle kernel paging request at fffffbfff807440b
[ 298.628512] #PF error: [normal kernel read fault]
[ 298.633018] PGD 124327067 P4D 124327067 PUD 11c1a3067 PMD 119eb2067 PTE 0
[ 298.638859] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 298.638859] CPU: 0 PID: 2997 Comm: iptables Not tainted 4.20.0+ #154
[ 298.638859] RIP: 0010:__mutex_lock+0x6b9/0x16a0
[ 298.638859] Code: c0 00 00 e8 89 82 ff ff 80 bd 8f fc ff ff 00 0f 85 d9 05 00 00 48 8b 85 80 fc ff ff 48 bf 00 00 00 00 00 fc ff df 48 c1 e8 03 <80> 3c 38 00 0f 85 1d 0e 00 00 48 8b 85 c8 fc ff ff 49 39 47 58 c6
[ 298.638859] RSP: 0018:ffff88810e7777a0 EFLAGS: 00010202
[ 298.638859] RAX: 1ffffffff807440b RBX: ffff888111bd4d80 RCX: 0000000000000000
[ 298.638859] RDX: 1ffff110235ff806 RSI: ffff888111bd5538 RDI: dffffc0000000000
[ 298.638859] RBP: ffff88810e777b30 R08: 0000000080000002 R09: 0000000000000000
[ 298.638859] R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff168a42c
[ 298.638859] R13: ffff888111bd4d80 R14: ffff8881040e9a05 R15: ffffffffc03a2000
[ 298.638859] FS: 00007f39e3758700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
[ 298.638859] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 298.638859] CR2: fffffbfff807440b CR3: 000000011243e000 CR4: 00000000001006f0
[ 298.638859] Call Trace:
[ 298.638859] ? mutex_lock_io_nested+0x1560/0x1560
[ 298.638859] ? kasan_kmalloc+0xa0/0xd0
[ 298.638859] ? kmem_cache_alloc+0x1c2/0x260
[ 298.638859] ? __alloc_file+0x92/0x3c0
[ 298.638859] ? alloc_empty_file+0x43/0x120
[ 298.638859] ? alloc_file_pseudo+0x220/0x330
[ 298.638859] ? sock_alloc_file+0x39/0x160
[ 298.638859] ? __sys_socket+0x113/0x1d0
[ 298.638859] ? __x64_sys_socket+0x6f/0xb0
[ 298.638859] ? do_syscall_64+0x138/0x560
[ 298.638859] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 298.638859] ? __alloc_file+0x92/0x3c0
[ 298.638859] ? init_object+0x6b/0x80
[ 298.638859] ? cyc2ns_read_end+0x10/0x10
[ 298.638859] ? cyc2ns_read_end+0x10/0x10
[ 298.638859] ? hlock_class+0x140/0x140
[ 298.638859] ? sched_clock_local+0xd4/0x140
[ 298.638859] ? sched_clock_local+0xd4/0x140
[ 298.638859] ? check_flags.part.37+0x440/0x440
[ 298.638859] ? __lock_acquire+0x4f90/0x4f90
[ 298.638859] ? set_rq_offline.part.89+0x140/0x140
[ ... ]
Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
show more ...
|
| 61fbf593 | 08-Jan-2019 |
Taehee Yoo <ap420073@gmail.com> |
net: bpfilter: restart bpfilter_umh when error occurred
The bpfilter_umh will be stopped via __stop_umh() when the bpfilter
error occurred.
The bpfilter_umh() couldn't start again because there is n
net: bpfilter: restart bpfilter_umh when error occurred
The bpfilter_umh will be stopped via __stop_umh() when the bpfilter
error occurred.
The bpfilter_umh() couldn't start again because there is no restart
routine.
The section of the bpfilter_umh_{start/end} is no longer .init.rodata
because these area should be reused in the restart routine. hence
the section name is changed to .bpfilter_umh.
The bpfilter_ops->start() is restart callback. it will be called when
bpfilter_umh is stopped.
The stop bit means bpfilter_umh is stopped. this bit is set by both
start and stop routine.
Before this patch,
Test commands:
$ iptables -vnL
$ kill -9 <pid of bpfilter_umh>
$ iptables -vnL
[ 480.045136] bpfilter: write fail -32
$ iptables -vnL
All iptables commands will fail.
After this patch,
Test commands:
$ iptables -vnL
$ kill -9 <pid of bpfilter_umh>
$ iptables -vnL
$ iptables -vnL
Now, all iptables commands will work.
Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
show more ...
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