From d93769405996dfc11d216ddbe415946617b5a494 Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Mon, 20 Jan 2020 17:01:50 +0100 Subject: [PATCH] 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"). --- 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 e7ce410845..b2f46160e7 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 7c2d4726f8..d1456c8ae4 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 65c260ab76..8a53a1088f 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]; } -- 2.43.5