btrfs: handle memory allocation failure in btrfs_csum_one_bio

Since f8a53bb ("btrfs: handle checksum generation in the storage layer") the failures of btrfs_csum_one_bio() are handled via bio_end_io(). This means, we can return BLK_STS_RESOURCE from btrfs_csum_one_bio() in case the allocation of the ordered sums fails. This also fixes a syzkaller report, where injecting a failure into the kvzalloc() call results in a BUG_ON(). Reported-by: [email protected] Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Anand Jain <[email protected]> Signed-off-by: Johannes Thumshirn <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>
google · May 17, 2023 · 806570c · 806570c
1 parent 7561551
commit 806570c
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
@@ -792,7 +792,9 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
 				sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
 						      bytes_left), GFP_KERNEL);
 				memalloc_nofs_restore(nofs_flag);
-				BUG_ON(!sums); /* -ENOMEM */
+				if (!sums)
+					return BLK_STS_RESOURCE;
+
 				sums->len = bytes_left;
 				ordered = btrfs_lookup_ordered_extent(inode,
 								offset);