From: Oleg Nesterov <oleg@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@console-pimps.org>,
Tejun Heo <htejun@gmail.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH for 3.1] ptrace: PTRACE_LISTEN forgets to unlock ->siglock
Date: Sun, 25 Sep 2011 19:46:22 +0200 [thread overview]
Message-ID: <20110925174622.GA18509@redhat.com> (raw)
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>
---
kernel/ptrace.c | 23 ++++++++++-------------
1 file changed, 10 insertions(+), 13 deletions(-)
--- 3.1/kernel/ptrace.c~1_PTRACE_LISTEN_siglock 2011-09-25 19:14:32.000000000 +0200
+++ 3.1/kernel/ptrace.c 2011-09-25 19:40:57.000000000 +0200
@@ -744,20 +744,17 @@ int ptrace_request(struct task_struct *c
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. */
next reply other threads:[~2011-09-25 17:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-25 17:46 Oleg Nesterov [this message]
2011-09-26 8:09 ` [PATCH for 3.1] ptrace: PTRACE_LISTEN forgets to unlock ->siglock Matt Fleming
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110925174622.GA18509@redhat.com \
--to=oleg@redhat.com \
--cc=htejun@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=matt@console-pimps.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox