public inbox for glibc-cvs@sourceware.org help / color / mirror / Atom feed
From: Florian Weimer <fw@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/release/2.34/master] malloc: Fix -Wuse-after-free warning in tst-mallocalign1 [BZ #26779] Date: Thu, 12 Jan 2023 06:22:02 +0000 (GMT) [thread overview] Message-ID: <20230112062202.5195A385B518@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=6484ae5b8c4d4314f748e4d3c9a9baa5385e57c5 commit 6484ae5b8c4d4314f748e4d3c9a9baa5385e57c5 Author: Carlos O'Donell <carlos@redhat.com> Date: Fri Jan 28 15:14:29 2022 -0500 malloc: Fix -Wuse-after-free warning in tst-mallocalign1 [BZ #26779] The test leaks bits from the freed pointer via the return value in ret, and the compiler correctly identifies this issue. We switch the test to use TEST_VERIFY and terminate the test if any of the pointers return an unexpected alignment. This fixes another -Wuse-after-free error when compiling glibc with gcc 12. Tested on x86_64 and i686 without regression. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> (cherry picked from commit 3a7bed5f5a527dbd87412551f41e42e63aeef07a) Diff: --- malloc/tst-mallocalign1.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/malloc/tst-mallocalign1.c b/malloc/tst-mallocalign1.c index 294e821afe..3e09ff30c4 100644 --- a/malloc/tst-mallocalign1.c +++ b/malloc/tst-mallocalign1.c @@ -20,6 +20,7 @@ #include <stdlib.h> #include <inttypes.h> #include <malloc-size.h> +#include <support/check.h> static void * test (size_t s) @@ -31,41 +32,42 @@ test (size_t s) return p; } +#define ALIGNED(p) (((uintptr_t )p & MALLOC_ALIGN_MASK) == 0) + static int do_test (void) { void *p; - int ret = 0; p = test (2); - ret |= (uintptr_t) p & MALLOC_ALIGN_MASK; + TEST_VERIFY (ALIGNED (p)); free (p); p = test (8); - ret |= (uintptr_t) p & MALLOC_ALIGN_MASK; + TEST_VERIFY (ALIGNED (p)); free (p); p = test (13); - ret |= (uintptr_t) p & MALLOC_ALIGN_MASK; + TEST_VERIFY (ALIGNED (p)); free (p); p = test (16); - ret |= (uintptr_t) p & MALLOC_ALIGN_MASK; + TEST_VERIFY (ALIGNED (p)); free (p); p = test (23); - ret |= (uintptr_t) p & MALLOC_ALIGN_MASK; + TEST_VERIFY (ALIGNED (p)); free (p); p = test (43); - ret |= (uintptr_t) p & MALLOC_ALIGN_MASK; + TEST_VERIFY (ALIGNED (p)); free (p); p = test (123); - ret |= (uintptr_t) p & MALLOC_ALIGN_MASK; + TEST_VERIFY (ALIGNED (p)); free (p); - return ret; + return 0; } #include <support/test-driver.c>
reply other threads:[~2023-01-12 6:22 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20230112062202.5195A385B518@sourceware.org \ --to=fw@sourceware.org \ --cc=glibc-cvs@sourceware.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).