From 540804b5c52065a87d826f7714b18a3ec0b269f9 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Mon, 4 Oct 2010 12:00:02 +0200 Subject: [PATCH] perf_events: Fix invalid pointer when pid is invalid This patch fixes an error in perf_event_open() when the pid provided by the user is invalid. find_lively_task_by_vpid() does not return NULL on error but an error code. Without the fix the error code was silently passed to find_get_context() which would eventually cause a invalid pointer dereference. Signed-off-by: Stephane Eranian Cc: peterz@infradead.org Cc: paulus@samba.org Cc: davem@davemloft.net Cc: fweisbec@gmail.com Cc: perfmon2-devel@lists.sf.net Cc: eranian@gmail.com Cc: robert.richter@amd.com LKML-Reference: <4ca9a5d1.e8e9d80a.3dbb.ffff8f2e@mx.google.com> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index c16158c77dfd..64507eaa2d9e 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -5616,8 +5616,13 @@ SYSCALL_DEFINE5(perf_event_open, } } - if (pid != -1) + if (pid != -1) { task = find_lively_task_by_vpid(pid); + if (IS_ERR(task)) { + err = PTR_ERR(task); + goto err_group_fd; + } + } /* * Get the target context (task or percpu): -- 2.20.1