Commit 3be0b3ed authored by Dan Carpenter's avatar Dan Carpenter Committed by David Howells
Browse files

netfs, fscache: Prevent Oops in fscache_put_cache() 



This function dereferences "cache" and then checks if it's
IS_ERR_OR_NULL().  Check first, then dereference.

Fixes: 9549332d ("fscache: Implement cache registration")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/e84bc740-3502-4f16-982a-a40d5676615c@moroto.mountain/ # v2
parent c40497d8

fs/netfs/fscache_cache.c

+2 −1
Original line number Diff line number Diff line
@@ -179,13 +179,14 @@ EXPORT_SYMBOL(fscache_acquire_cache); 
void fscache_put_cache(struct fscache_cache *cache,

		       enum fscache_cache_trace where)

{

	unsigned int debug_id = cache->debug_id;

	unsigned int debug_id;

	bool zero;

	int ref;



	if (IS_ERR_OR_NULL(cache))

		return;



	debug_id = cache->debug_id;

	zero = __refcount_dec_and_test(&cache->ref, &ref);

	trace_fscache_cache(debug_id, ref - 1, where);