commit 68ee0f704cb81e9ad0a78c644a83e1e9cd2ee578 Author: Siddhesh Poyarekar <siddhesh@sourceware.org> Date: Tue Jan 21 16:11:06 2025 -0500 Fix underallocation of abort_msg_s struct (CVE-2025-0395) Include the space needed to store the length of the message itself, in addition to the message string. This resolves BZ #32582. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed: Adhemerval Zanella <adhemerval.zanella@linaro.org> Conflicts: sysdeps/posix/libc_fatal.c: Adjust for skipped upstream commit: cca9684f2d7a74fc0b28bfb1859955e0e28d7b4b (stdio: Clean up __libc_message after unconditional abort) diff --git a/assert/assert.c b/assert/assert.c index 8ed691bd323c876a..f81d751cdab5ff92 100644 --- a/assert/assert.c +++ b/assert/assert.c @@ -18,6 +18,7 @@ #include <assert.h> #include <atomic.h> #include <ldsodefs.h> +#include <libc-pointer-arith.h> #include <libintl.h> #include <stdio.h> #include <stdlib.h> @@ -64,7 +65,8 @@ __assert_fail_base (const char *fmt, const char *assertion, const char *file, (void) __fxprintf (NULL, "%s", str); (void) fflush (stderr); - total = (total + 1 + GLRO(dl_pagesize) - 1) & ~(GLRO(dl_pagesize) - 1); + total = ALIGN_UP (total + sizeof (struct abort_msg_s) + 1, + GLRO(dl_pagesize)); struct abort_msg_s *buf = __mmap (NULL, total, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0); if (__glibc_likely (buf != MAP_FAILED)) diff --git a/sysdeps/posix/libc_fatal.c b/sysdeps/posix/libc_fatal.c index 89a20080e16558b5..89d5782a44e251a8 100644 --- a/sysdeps/posix/libc_fatal.c +++ b/sysdeps/posix/libc_fatal.c @@ -20,6 +20,7 @@ #include <errno.h> #include <fcntl.h> #include <ldsodefs.h> +#include <libc-pointer-arith.h> #include <paths.h> #include <stdarg.h> #include <stdbool.h> @@ -147,8 +148,8 @@ __libc_message (enum __libc_message_action action, const char *fmt, ...) if ((action & do_abort)) { - total = ((total + 1 + GLRO(dl_pagesize) - 1) - & ~(GLRO(dl_pagesize) - 1)); + total = ALIGN_UP (total + sizeof (struct abort_msg_s) + 1, + GLRO(dl_pagesize)); struct abort_msg_s *buf = __mmap (NULL, total, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);