aboutsummaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorRoland Dreier <roland@purestorage.com>2011-03-28 14:13:35 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2011-04-14 13:02:02 -0700
commit76e61a187353bb6798284196b874938a8fbe3db9 (patch)
treecacd81c8eec55bcb8c8b704289c83a72aad1c9df /kernel
parent68abeb71d51d40b805cd3596cfc4f45105e57cad (diff)
downloadlinux-linaro-android-76e61a187353bb6798284196b874938a8fbe3db9.tar.gz
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/signal.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 31751868de8..bf11d2697e9 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2423,7 +2423,7 @@ 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;
@@ -2443,7 +2443,7 @@ long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info)
/* 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;