Commit 38aeb071 authored Jan 30, 2020 by Dan Carpenter Committed by Linus Torvalds Jan 31, 2020

zswap: potential NULL dereference on error in init_zswap()

The "pool" pointer can be NULL at the end of the init_zswap().  (We
would allocate a new pool later in that situation)

So in the error handling then we need to make sure pool is a valid
pointer before calling "zswap_pool_destroy(pool);" because that function
dereferences the argument.

Link: http://lkml.kernel.org/r/20200114050902.og32fkllkod5ycf5@kili.mountain


Fixes: 93d4dfa9fbd0 ("mm/zswap.c: add allocation hysteresis if pool limit is hit")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 45190f01

mm/zswap.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1359,6 +1359,7 @@ static int __init init_zswap(void)
		return 0;

		fallback_fail:
		if (pool)
		zswap_pool_destroy(pool);
		hp_fail:
		cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE);