diff options
| author | Aleksa Sarai <asarai@suse.com> | 2017-08-06 07:41:41 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-10 13:18:19 +0300 |
| commit | 74dc3384fc7983b78cc46ebb1824968a3db85eb1 (patch) | |
| tree | e896440f183791c28162dd72dfb60470aac80d16 /fs/proc/base.c | |
| parent | 18f08dae19990f5fffde92e3a63e0d90cda0f1a8 (diff) | |
| download | linux-74dc3384fc7983b78cc46ebb1824968a3db85eb1.tar.xz | |
sched/debug: Use task_pid_nr_ns in /proc/$pid/sched
It appears as though the addition of the PID namespace did not update
the output code for /proc/*/sched, which resulted in it providing PIDs
that were not self-consistent with the /proc mount. This additionally
made it trivial to detect whether a process was inside &init_pid_ns from
userspace, making container detection trivial:
https://github.com/jessfraz/amicontained
This leads to situations such as:
% unshare -pmf
% mount -t proc proc /proc
% head -n1 /proc/1/sched
head (10047, #threads: 1)
Fix this by just using task_pid_nr_ns for the output of /proc/*/sched.
All of the other uses of task_pid_nr in kernel/sched/debug.c are from a
sysctl context and thus don't need to be namespaced.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jess Frazelle <acidburn@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: cyphar@cyphar.com
Link: http://lkml.kernel.org/r/20170806044141.5093-1-asarai@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'fs/proc/base.c')
| -rw-r--r-- | fs/proc/base.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 719c2e943ea1..98fd8f6df851 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1408,12 +1408,13 @@ static const struct file_operations proc_fail_nth_operations = { static int sched_show(struct seq_file *m, void *v) { struct inode *inode = m->private; + struct pid_namespace *ns = inode->i_sb->s_fs_info; struct task_struct *p; p = get_proc_task(inode); if (!p) return -ESRCH; - proc_sched_show_task(p, m); + proc_sched_show_task(p, ns, m); put_task_struct(p); |