[PATCH 5.12 119/161] ext4: fix memory leak in ext4_mb_init_backend on error path.

From: Greg Kroah-Hartman
Date: Tue Jun 08 2021 - 15:33:28 EST


From: Phillip Potter <phil@xxxxxxxxxxxxxxxx>

commit a8867f4e3809050571c98de7a2d465aff5e4daf5 upstream.

Fix a memory leak discovered by syzbot when a file system is corrupted
with an illegally large s_log_groups_per_flex.

Reported-by: syzbot+aa12d6106ea4ca1b6aae@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Phillip Potter <phil@xxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxx
Link: https://lore.kernel.org/r/20210412073837.1686-1-phil@xxxxxxxxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/mballoc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2715,7 +2715,7 @@ static int ext4_mb_init_backend(struct s
*/
if (sbi->s_es->s_log_groups_per_flex >= 32) {
ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group");
- goto err_freesgi;
+ goto err_freebuddy;
}
sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex,
BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9));