[RFC PATCH 6/6] perf: Fix double put_ctx

From: Frederic Weisbecker
Date: Thu Jul 01 2010 - 11:37:11 EST


If we call free_event on fail case of event creation, it
already put the context. The falldown goto, though, also
does a put_ctx, which might dereference a freed context.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: Paul Mundt <lethal@xxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
---
kernel/perf_event.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index b6e854f..925b53e 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -5364,6 +5364,8 @@ SYSCALL_DEFINE5(perf_event_open,

err_free_put_context:
free_event(event);
+ fput_light(group_file, fput_needed);
+ goto err_fd;
err_put_context:
fput_light(group_file, fput_needed);
put_ctx(ctx);
--
1.6.2.3

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