diff options
| author | Roland Dreier <roland@purestorage.com> | 2011-03-28 14:13:35 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2011-04-30 16:53:25 +0200 |
| commit | 92bf9b9866298c3b7c416eb07c9542d01e8b3ae6 (patch) | |
| tree | f99484bc6bd1633397b5cc5db84a3bc6c2d81d9c | |
| parent | 99ea3562f964a4349c004bd2a391f625cd7093f7 (diff) | |
Relax si_code check in rt_sigqueueinfo and rt_tgsigqueueinfo
commit 243b422af9ea9af4ead07a8ad54c90d4f9b6081a upstream.
Commit da48524eb206 ("Prevent rt_sigqueueinfo and rt_tgsigqueueinfo
from spoofing the signal code") made the check on si_code too strict.
There are several legitimate places where glibc wants to queue a
negative si_code different from SI_QUEUE:
- This was first noticed with glibc's aio implementation, which wants
to queue a signal with si_code SI_ASYNCIO; the current kernel
causes glibc's tst-aio4 test to fail because rt_sigqueueinfo()
fails with EPERM.
- Further examination of the glibc source shows that getaddrinfo_a()
wants to use SI_ASYNCNL (which the kernel does not even define).
The timer_create() fallback code wants to queue signals with SI_TIMER.
As suggested by Oleg Nesterov <oleg@redhat.com>, loosen the check to
forbid only the problematic SI_TKILL case.
Reported-by: Klaus Dittrich <kladit@arcor.de>
Acked-by: Julien Tinnes <jln@google.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[wt: 2.6.27 has no rt_tgsigqueueinfo()]
| -rw-r--r-- | kernel/signal.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 56d815dea38..b1506fb1d74 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2296,7 +2296,7 @@ SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, /* Not even root can pretend to send signals from the kernel. * Nor can they impersonate a kill()/tgkill(), which adds source info. */ - if (info.si_code != SI_QUEUE) { + if (info.si_code >= 0 || info.si_code == SI_TKILL) { /* We used to allow any < 0 si_code */ WARN_ON_ONCE(info.si_code < 0); return -EPERM; |