arm64: compat_sys_sigsuspend: init local blocked mask not current process mask

Message ID 1361796007-20143-1-git-send-email-ryan.harkin@linaro.org
State New
Headers show

Commit Message

Ryan Harkin Feb. 25, 2013, 12:40 p.m.
The original version changed the signal mask in the current process, and then passed an unitialized variable to sigsuspend, which in turn, besides the other work, sets current->blocked.

The value of mask, passed from a process, was effectively overwritten by some random value.  If the random value was zero, all signals were blocked and pipes no longer work.

Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
---
 arch/arm64/kernel/signal32.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Catalin Marinas Feb. 25, 2013, 12:58 p.m. | #1
On Mon, Feb 25, 2013 at 12:40:07PM +0000, Ryan Harkin wrote:
> The original version changed the signal mask in the current process,
> and then passed an unitialized variable to sigsuspend, which in turn,
> besides the other work, sets current->blocked.
> 
> The value of mask, passed from a process, was effectively overwritten
> by some random value.  If the random value was zero, all signals were
> blocked and pipes no longer work.
> 
> Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>

Thanks for the patch. It's a candidate for stable since mainline no
longer has this function, removed by commit 84b9e9b40 (arm64: switch
compat to generic old sigsuspend).

Patch

diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index a4db3d2..0bc9461 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c
@@ -347,7 +347,7 @@  asmlinkage int compat_sys_sigsuspend(int restart, compat_ulong_t oldmask,
 {
 	sigset_t blocked;
 
-	siginitset(&current->blocked, mask);
+	siginitset(&blocked, mask);
 	return sigsuspend(&blocked);
 }