[PATCH 2/8] ftrace: Fix possible NULL dereferencing in __ftrace_hash_rec_update

[Jiri Olsa]

We need to check the existence of the other_hash before
we touch its count variable.

This issue is hit only when non global ftrace_ops is used.
The global ftrace_ops is initialized with empty hashes.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 kernel/trace/ftrace.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 09007c0..7eb702f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1372,7 +1372,8 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 			if (filter_hash && in_hash && !in_other_hash)
 				match = 1;
 			else if (!filter_hash && in_hash &&
-				 (in_other_hash || !other_hash->count))
+				 (in_other_hash ||
+				  !other_hash || !other_hash->count))
 				match = 1;
 		}
 		if (!match)
-- 
1.7.1

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