[glibc/release/2.29/master] Fix array overflow in backtrace on PowerPC (bug 25423)
Patricia Franklin
patsy@sourceware.org
Wed Mar 18 20:46:28 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a318448f7aca169f7795d9d300c525d96f914af0
commit a318448f7aca169f7795d9d300c525d96f914af0
Author: Andreas Schwab <schwab@suse.de>
Date: Mon Jan 20 17:01:50 2020 +0100
Fix array overflow in backtrace on PowerPC (bug 25423)
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)
Diff:
---
debug/tst-backtrace5.c | 12 ++++++++++++
sysdeps/powerpc/powerpc32/backtrace.c | 2 ++
sysdeps/powerpc/powerpc64/backtrace.c | 2 ++
3 files changed, 16 insertions(+)
diff --git a/debug/tst-backtrace5.c b/debug/tst-backtrace5.c
index 5a5ce8bc79..aed5ee4c94 100644
--- a/debug/tst-backtrace5.c
+++ b/debug/tst-backtrace5.c
@@ -89,6 +89,18 @@ 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 857a8aad7b..dc187a8f20 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 7a167838d9..ce038a139f 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];
}
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