From: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
To: libc-stable@sourceware.org
Cc: Andreas Schwab <schwab@suse.de>
Subject: [2.28 COMMITTED] Fix array overflow in backtrace on PowerPC (bug 25423)
Date: Fri, 20 Mar 2020 18:03:32 -0300 [thread overview]
Message-ID: <20200320210333.202385-1-tuliom@linux.ibm.com> (raw)
From: Andreas Schwab <schwab@suse.de>
When unwinding through a signal frame the backtrace function on PowerPC
didn't check array bounds when storing the frame address. Fixes commit
d400dcac5e ("PowerPC: fix backtrace to handle signal trampolines").
(cherry picked from commit d93769405996dfc11d216ddbe415946617b5a494)
---
NEWS | 1 +
debug/tst-backtrace5.c | 12 ++++++++++++
sysdeps/powerpc/powerpc32/backtrace.c | 2 ++
sysdeps/powerpc/powerpc64/backtrace.c | 2 ++
4 files changed, 17 insertions(+)
diff --git a/NEWS b/NEWS
index ace1b86fdb..038541c83b 100644
--- a/NEWS
+++ b/NEWS
@@ -73,6 +73,7 @@ The following bugs are resolved with this release:
[25204] Ignore LD_PREFER_MAP_32BIT_EXEC for SUID programs
[25225] ld.so fails to link on x86 if GCC defaults to -fcf-protection
[25232] No const correctness for strchr et al. for Clang++
+ [25423] Array overflow in backtrace on powerpc
Security related changes:
diff --git a/debug/tst-backtrace5.c b/debug/tst-backtrace5.c
index 0e6fb1a024..a117f1544f 100644
--- a/debug/tst-backtrace5.c
+++ b/debug/tst-backtrace5.c
@@ -88,6 +88,18 @@ handle_signal (int signum)
}
/* Symbol names are not available for static functions, so we do not
check do_test. */
+
+ /* Check that backtrace does not return more than what fits in the array
+ (bug 25423). */
+ for (int j = 0; j < NUM_FUNCTIONS; j++)
+ {
+ n = backtrace (addresses, j);
+ if (n > j)
+ {
+ FAIL ();
+ return;
+ }
+ }
}
NO_INLINE int
diff --git a/sysdeps/powerpc/powerpc32/backtrace.c b/sysdeps/powerpc/powerpc32/backtrace.c
index 5422fdd50d..c7b64f9e9b 100644
--- a/sysdeps/powerpc/powerpc32/backtrace.c
+++ b/sysdeps/powerpc/powerpc32/backtrace.c
@@ -114,6 +114,8 @@ __backtrace (void **array, int size)
}
if (gregset)
{
+ if (count + 1 == size)
+ break;
array[++count] = (void*)((*gregset)[PT_NIP]);
current = (void*)((*gregset)[PT_R1]);
}
diff --git a/sysdeps/powerpc/powerpc64/backtrace.c b/sysdeps/powerpc/powerpc64/backtrace.c
index c0c4b48262..0acf17b37e 100644
--- a/sysdeps/powerpc/powerpc64/backtrace.c
+++ b/sysdeps/powerpc/powerpc64/backtrace.c
@@ -87,6 +87,8 @@ __backtrace (void **array, int size)
if (is_sigtramp_address (current->return_address))
{
struct signal_frame_64 *sigframe = (struct signal_frame_64*) current;
+ if (count + 1 == size)
+ break;
array[++count] = (void*) sigframe->uc.uc_mcontext.gp_regs[PT_NIP];
current = (void*) sigframe->uc.uc_mcontext.gp_regs[PT_R1];
}
--
2.24.1
next reply other threads:[~2020-03-20 21:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-20 21:03 Tulio Magno Quites Machado Filho [this message]
2020-03-20 21:03 ` [2.28 COMMITTED] Fix use-after-free in glob when expanding ~user (bug 25414) Tulio Magno Quites Machado Filho
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