4.9-stable review patch. If anyone has any objections, please let me know.
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From: Jiri Olsa jolsa@kernel.org
commit 78b562fbfa2cf0a9fcb23c3154756b690f4905c1 upstream.
Return immediately when we find issue in the user stack checks. The error value could get overwritten by following check for PERF_SAMPLE_REGS_INTR.
Signed-off-by: Jiri Olsa jolsa@kernel.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andi Kleen andi@firstfloor.org Cc: H. Peter Anvin hpa@zytor.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Cc: Thomas Gleixner tglx@linutronix.de Cc: syzkaller-bugs@googlegroups.com Cc: x86@kernel.org Fixes: 60e2364e60e8 ("perf: Add ability to sample machine state on interrupt") Link: http://lkml.kernel.org/r/20180415092352.12403-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9456,9 +9456,9 @@ static int perf_copy_attr(struct perf_ev * __u16 sample size limit. */ if (attr->sample_stack_user >= USHRT_MAX) - ret = -EINVAL; + return -EINVAL; else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) - ret = -EINVAL; + return -EINVAL; }
if (attr->sample_type & PERF_SAMPLE_REGS_INTR)