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| author | Bernd Edlinger <bernd.edlinger@hotmail.de> | 2020-03-20 21:27:24 +0100 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-03-25 10:04:01 -0500 |
| commit | 2db9dbf71bf98d02a0bf33e798e5bfd2a9944696 (patch) | |
| tree | b63a4232ab077b356f26635dbb9bb971914933a8 /fs/proc | |
| parent | 454e3126cb842388e22df6b3ac3da44062c00765 (diff) | |
| download | linux-2db9dbf71bf98d02a0bf33e798e5bfd2a9944696.tar.gz linux-2db9dbf71bf98d02a0bf33e798e5bfd2a9944696.tar.bz2 linux-2db9dbf71bf98d02a0bf33e798e5bfd2a9944696.zip | |
proc: Use new infrastructure to fix deadlocks in execve
This changes lock_trace to use the new exec_update_mutex
instead of cred_guard_mutex.
This fixes possible deadlocks when the trace is accessing
/proc/$pid/stack for instance.
This should be safe, as the credentials are only used for reading,
and task->mm is updated on execve under the new exec_update_mutex.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/base.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index e7efe9d6f3d6..a278fda0458b 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -405,11 +405,11 @@ print0: static int lock_trace(struct task_struct *task) { - int err = mutex_lock_killable(&task->signal->cred_guard_mutex); + int err = mutex_lock_killable(&task->signal->exec_update_mutex); if (err) return err; if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { - mutex_unlock(&task->signal->cred_guard_mutex); + mutex_unlock(&task->signal->exec_update_mutex); return -EPERM; } return 0; @@ -417,7 +417,7 @@ static int lock_trace(struct task_struct *task) static void unlock_trace(struct task_struct *task) { - mutex_unlock(&task->signal->cred_guard_mutex); + mutex_unlock(&task->signal->exec_update_mutex); } #ifdef CONFIG_STACKTRACE |