From: SeungJu Cheon Date: Thu, 2 Apr 2026 16:04:10 +0000 (+0900) Subject: perf header: Validate build_id filename length to prevent buffer overflow X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=85a9a4abcdc09ee941273c99d3ad0bc2ddef09ea;p=thirdparty%2Flinux.git perf header: Validate build_id filename length to prevent buffer overflow The build_id parsing functions calculate a filename length from the event header size and read directly into a stack buffer of PATH_MAX bytes without bounds checking. A malformed perf.data file with a crafted header.size can cause the length to be negative or exceed PATH_MAX, resulting in a stack buffer overflow. Add bounds checking for the filename length in both perf_header__read_build_ids() and the ABI quirk variant. Print a warning message when invalid length is detected. Signed-off-by: SeungJu Cheon Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim --- diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 9142a8ba40195..9ffc0f4ca6d13 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2545,6 +2545,11 @@ static int perf_header__read_build_ids_abi_quirk(struct perf_header *header, perf_event_header__bswap(&old_bev.header); len = old_bev.header.size - sizeof(old_bev); + if (len < 0 || len >= PATH_MAX) { + pr_warning("invalid build_id filename length %zd\n", len); + return -1; + } + if (readn(input, filename, len) != len) return -1; @@ -2587,6 +2592,11 @@ static int perf_header__read_build_ids(struct perf_header *header, perf_event_header__bswap(&bev.header); len = bev.header.size - sizeof(bev); + if (len < 0 || len >= PATH_MAX) { + pr_warning("invalid build_id filename length %zd\n", len); + goto out; + } + if (readn(input, filename, len) != len) goto out; /*