From c6a6c9694aadc4c3ab8d89bdd44aed3eab1e43c6 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 10 May 2024 18:22:53 +0300 Subject: [PATCH] ext4: fix error pointer dereference in ext4_mb_load_buddy_gfp() This code calls folio_put() on an error pointer which will lead to a crash. Check for both error pointers and NULL pointers before calling folio_put(). Fixes: 5eea586b47f0 ("ext4: convert bd_buddy_page to bd_buddy_folio") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/eaafa1d9-a61c-4af4-9f97-d3ad72c60200@moroto.mountain Signed-off-by: Theodore Ts'o --- fs/ext4/mballoc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 648989c125f2..9dda9cd68ab2 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1717,7 +1717,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group, return 0; err: - if (folio) + if (!IS_ERR_OR_NULL(folio)) folio_put(folio); if (e4b->bd_bitmap_folio) folio_put(e4b->bd_bitmap_folio);