[PATCH] mm/zswap: fix error pointer free in zswap_cpu_comp_prepare()

[Pavel Butsykin]

crypto_alloc_acomp_node() may return ERR_PTR(), but the fail path checks
only for NULL and can pass an error pointer to crypto_free_acomp().
Use IS_ERR_OR_NULL() to only free valid acomp instances.

Fixes: 779b9955f643 ("mm: zswap: move allocations during CPU init outside the lock")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Pavel Butsykin <pbutsykin@xxxxxxxxxxxxxx>
---
 mm/zswap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index 5d0f8b13a958..ac9b7a60736b 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -787,7 +787,7 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
 	return 0;
 
 fail:
-	if (acomp)
+	if (!IS_ERR_OR_NULL(acomp))
 		crypto_free_acomp(acomp);
 	kfree(buffer);
 	return ret;
-- 
2.52.0