From 27389d7823f573be8eaff32fb4abe564e181eb71 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Thu, 4 Jul 2013 16:20:27 +0300 Subject: [PATCH] perf tools: Validate perf event header size The 'size' variable includes the header so must be at least 'sizeof(struct perf_event_header)'. Error out immediately if that is not the case. Also don't byte-swap the header until it is actually "fetched" from the mmap region. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1372944040-32690-9-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/session.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 6b71b88..951a1cf 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1094,8 +1094,10 @@ more: perf_event_header__bswap(&event->header); size = event->header.size; - if (size == 0) - size = 8; + if (size < sizeof(struct perf_event_header)) { + pr_err("bad event header size\n"); + goto out_err; + } if (size > cur_size) { void *new = realloc(buf, size); @@ -1164,8 +1166,12 @@ fetch_mmaped_event(struct perf_session *session, if (session->header.needs_swap) perf_event_header__bswap(&event->header); - if (head + event->header.size > mmap_size) + if (head + event->header.size > mmap_size) { + /* We're not fetching the event so swap back again */ + if (session->header.needs_swap) + perf_event_header__bswap(&event->header); return NULL; + } return event; } @@ -1245,7 +1251,7 @@ more: size = event->header.size; - if (size == 0 || + if (size < sizeof(struct perf_event_header) || perf_session__process_event(session, event, tool, file_pos) < 0) { pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n", file_offset + head, event->header.size, -- 2.7.4