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 d937694059)
This commit is contained in:
Andreas Schwab 2020-01-20 17:01:50 +01:00 committed by Tulio Magno Quites Machado Filho
parent 2dc2d678e9
commit 37db4539dd
4 changed files with 17 additions and 0 deletions

1
NEWS
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@ -190,6 +190,7 @@ The following bugs are resolved with this release:
[24155] x32 memcmp can treat positive length as 0 (if sign bit in RDX is set) (CVE-2019-7309)
[25203] libio: Disable vtable validation for pre-2.1 interposed handles
[25204] Ignore LD_PREFER_MAP_32BIT_EXEC for SUID programs
[25423] Array overflow in backtrace on powerpc
Version 2.26

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@ -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

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@ -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]);
}

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@ -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];
}