lkml.org 
[lkml]   [2007]   [Oct]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 1/3] signal(i386): alternative signal stack wraparound occurs
Fixing alternative signal stack wraparound.

If a process uses alternative signal stack by using sigaltstack()
and that stack overflow, stack wraparound occurs.
This patch checks whether the signal frame is on the alternative
stack. If the frame is not on there, kill a signal SIGSEGV to the process forcedly
then the process will be terminated.

This patch is for i386,version is 2.6.23-rc8.

Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com>

diff -pur linux-2.6.23-rc8.orig/arch/i386/kernel/signal.c linux-2.6.23-rc8/arch/i386/kernel/signal.c
--- linux-2.6.23-rc8.orig/arch/i386/kernel/signal.c 2007-09-26 09:44:08.000000000 +0900
+++ linux-2.6.23-rc8/arch/i386/kernel/signal.c 2007-09-26 13:14:25.000000000 +0900
@@ -332,6 +332,10 @@ static int setup_frame(int sig, struct k

frame = get_sigframe(ka, regs, sizeof(*frame));

+ if ((ka->sa.sa_flags & SA_ONSTACK) &&
+ !sas_ss_flags((unsigned long)frame))
+ goto give_sigsegv;
+
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;

@@ -425,6 +429,10 @@ static int setup_rt_frame(int sig, struc

frame = get_sigframe(ka, regs, sizeof(*frame));

+ if ((ka->sa.sa_flags & SA_ONSTACK) &&
+ !sas_ss_flags((unsigned long)frame))
+ goto give_sigsegv;
+
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-10-03 10:11    [W:0.038 / U:0.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site