commit 078dacb5cfaf689fb3e885d3791b8b15dde94db8
author Dan Carpenter <dan.carpenter@linaro.org> Wed Jul 26 09:59:04 2023 +0300
committer Tom Rini <trini@konsulko.com> Tue Aug 08 17:05:43 2023 -0400
tree 406d397a264ad31bee75b899e4ea2581a4f94574
parent 8fb3cf1666506b1259d2742ab8e63b93700be95d

fs: btrfs: Prevent error pointer dereference in list_subvolums()

If btrfs_read_fs_root() fails with -ENOENT, then we go to the next
entry.  Fine.  But if it fails for a different reason then we need
to clean up and return an error code.  In the current code it
doesn't clean up but instead dereferences "root" and crashes.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Qu Wenruo <wqu@suse.com>

fs/btrfs/subvolume.c

diff --git a/fs/btrfs/subvolume.c b/fs/btrfs/subvolume.c
index d446e7a..68ca7e4 100644
--- a/fs/btrfs/subvolume.c
+++ b/fs/btrfs/subvolume.c
@@ -199,6 +199,7 @@
 			ret = PTR_ERR(root);
 			if (ret == -ENOENT)
 				goto next;
+			goto out;
 		}
 		ret = list_one_subvol(root, result);
 		if (ret < 0)