[PATCH] quota: Fix memory leak when handling corrupted quota file

From: Jan Kara
Date: Tue Dec 22 2020 - 06:09:53 EST


When checking corrupted quota file we can bail out and leak allocated
info structure. Properly free info structure on error return.

Reported-by: syzbot+77779c9b52ab78154b08@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 11c514a99bb9 ("quota: Sanity-check quota file headers on load")
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/quota/quota_v2.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c
index c21106557a37..b1467f3921c2 100644
--- a/fs/quota/quota_v2.c
+++ b/fs/quota/quota_v2.c
@@ -164,19 +164,24 @@ static int v2_read_file_info(struct super_block *sb, int type)
quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
(loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
i_size_read(sb_dqopt(sb)->files[type]));
- goto out;
+ goto out_free;
}
if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) {
quota_error(sb, "Free block number too big (%u >= %u).",
qinfo->dqi_free_blk, qinfo->dqi_blocks);
- goto out;
+ goto out_free;
}
if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
quota_error(sb, "Block with free entry too big (%u >= %u).",
qinfo->dqi_free_entry, qinfo->dqi_blocks);
- goto out;
+ goto out_free;
}
ret = 0;
+out_free:
+ if (ret) {
+ kfree(info->dqi_priv);
+ info->dqi_priv = NULL;
+ }
out:
up_read(&dqopt->dqio_sem);
return ret;
--
2.16.4


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