From e294a2074f0059de7c69b30fe3048fe61f971b83 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Mon, 28 Mar 2011 14:13:35 -0700 Subject: 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 , loosen the check to forbid only the problematic SI_TKILL case. Reported-by: Klaus Dittrich Acked-by: Julien Tinnes Cc: Signed-off-by: Roland Dreier Signed-off-by: Linus Torvalds Tested-by: Krzysztof Mazur Signed-off-by: Willy Tarreau --- kernel/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/signal.c b/kernel/signal.c index b368505a7b22f..461885de3ff24 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1076,7 +1076,7 @@ sys_rt_sigqueueinfo(int pid, int sig, siginfo_t *uinfo) /* 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 */ return -EPERM; } -- cgit 1.2.3-korg