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| author | Oleg Nesterov <oleg@redhat.com> | 2011-09-25 19:46:22 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-09-25 11:02:00 -0700 |
| commit | f9d81f61c84aca693bc353dfef4b8c36c2e5e1b5 (patch) | |
| tree | adf2453955649221a9a178d7d19d5b1e71f3fe67 /kernel | |
| parent | b172e38e435a158cc84169d5b9127a8dd8d21e76 (diff) | |
| download | lwn-f9d81f61c84aca693bc353dfef4b8c36c2e5e1b5.tar.gz lwn-f9d81f61c84aca693bc353dfef4b8c36c2e5e1b5.zip | |
ptrace: PTRACE_LISTEN forgets to unlock ->siglock
If PTRACE_LISTEN fails after lock_task_sighand() it doesn't drop ->siglock.
Reported-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/ptrace.c | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 9de3ecfd20f9..a70d2a5d8c7b 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -744,20 +744,17 @@ int ptrace_request(struct task_struct *child, long request, break; si = child->last_siginfo; - if (unlikely(!si || si->si_code >> 8 != PTRACE_EVENT_STOP)) - break; - - child->jobctl |= JOBCTL_LISTENING; - - /* - * If NOTIFY is set, it means event happened between start - * of this trap and now. Trigger re-trap immediately. - */ - if (child->jobctl & JOBCTL_TRAP_NOTIFY) - signal_wake_up(child, true); - + if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { + child->jobctl |= JOBCTL_LISTENING; + /* + * If NOTIFY is set, it means event happened between + * start of this trap and now. Trigger re-trap. + */ + if (child->jobctl & JOBCTL_TRAP_NOTIFY) + signal_wake_up(child, true); + ret = 0; + } unlock_task_sighand(child, &flags); - ret = 0; break; case PTRACE_DETACH: /* detach a process that was attached. */ |