From: Arnaldo Carvalho de Melo <[email protected]> Vince reported that when fuzzing the userland perf tool with a bogus perf.data file he got into a infinite loop in 'perf report'.
Changing the return of fetch_mmaped_event() to ERR_PTR(-EINVAL) for that case gets us out of that infinite loop. Reported-by: Vince Weaver <[email protected]> Tested-by: Vince Weaver <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/session.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 11e6093c941b..b9fe71d11bf6 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <errno.h> #include <inttypes.h> +#include <linux/err.h> #include <linux/kernel.h> #include <linux/zalloc.h> #include <traceevent/event-parse.h> @@ -1955,7 +1956,9 @@ fetch_mmaped_event(struct perf_session *session, /* We're not fetching the event so swap back again */ if (session->header.needs_swap) perf_event_header__bswap(&event->header); - return NULL; + pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx: fuzzed perf.data?\n", + __func__, head, event->header.size, mmap_size); + return ERR_PTR(-EINVAL); } return event; @@ -1973,6 +1976,9 @@ static int __perf_session__process_decomp_events(struct perf_session *session) while (decomp->head < decomp->size && !session_done()) { union perf_event *event = fetch_mmaped_event(session, decomp->head, decomp->size, decomp->data); + if (IS_ERR(event)) + return PTR_ERR(event); + if (!event) break; @@ -2072,6 +2078,9 @@ reader__process_events(struct reader *rd, struct perf_session *session, more: event = fetch_mmaped_event(session, head, mmap_size, buf); + if (IS_ERR(event)) + return PTR_ERR(event); + if (!event) { if (mmaps[map_idx]) { munmap(mmaps[map_idx], mmap_size); -- 2.21.0
