From patchwork Tue Jan 21 11:31:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Schwab X-Patchwork-Id: 37449 X-Patchwork-Delegate: azanella@linux.vnet.ibm.com Received: (qmail 92978 invoked by alias); 21 Jan 2020 11:31:45 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 92969 invoked by uid 89); 21 Jan 2020 11:31:44 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-15.3 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_PASS autolearn=ham version=3.3.1 spammy=labs, Labs, fingerprint X-HELO: mx2.suse.de From: Andreas Schwab To: libc-alpha@sourceware.org Subject: [PATCH] Fix array overflow in backtrace on PowerPC (bug 25423) X-Yow: LOOK!! Sullen American teens wearing MADRAS shorts and ``Flock of Seagulls'' HAIRCUTS! Date: Tue, 21 Jan 2020 12:31:27 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 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"). Reviewed-by: Adhemerval Zanella --- 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]; }