[PATCH] Fix uninitialized variable in ext4_inlinedir_to_tree

[PATCH] Fix uninitialized variable in ext4_inlinedir_to_tree

[Xiaxi Shen]

Syzbot has found an uninit-value bug in ext4_inlinedir_to_tree

This error happens because ext4_inlinedir_to_tree does not
handle the case when ext4fs_dirhash returns an error

This can be avoided by checking the return value of ext4fs_dirhash 
and propagating the error,
similar to how it's done with ext4_htree_store_dirent

Signed-off-by: Xiaxi Shen <shenxiaxi26@gmail.com>
Reported-and-tested-by: syzbot+eaba5abe296837a640c0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=eaba5abe296837a640c0
---
 fs/ext4/inline.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index d5bd1e3a5d36..e7a09a99837b 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1410,7 +1410,11 @@ int ext4_inlinedir_to_tree(struct file *dir_file,
 			hinfo->hash = EXT4_DIRENT_HASH(de);
 			hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de);
 		} else {
-			ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
+			err = ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
+			if (err) {
+				ret = err;
+				goto out;
+			}
 		}
 		if ((hinfo->hash < start_hash) ||
 		    ((hinfo->hash == start_hash) &&
-- 
2.34.1

Re: [PATCH] Fix uninitialized variable in ext4_inlinedir_to_tree

[Theodore Ts'o]

On Tue, 30 Apr 2024 20:30:17 -0700, Xiaxi Shen wrote:
> Syzbot has found an uninit-value bug in ext4_inlinedir_to_tree
> 
> This error happens because ext4_inlinedir_to_tree does not
> handle the case when ext4fs_dirhash returns an error
> 
> This can be avoided by checking the return value of ext4fs_dirhash
> and propagating the error,
> similar to how it's done with ext4_htree_store_dirent
> 
> [...]

Applied, thanks!

[1/1] Fix uninitialized variable in ext4_inlinedir_to_tree
      commit: 8dc9c3da79c84b13fdb135e2fb0a149a8175bffe

Best regards,
-- 
Theodore Ts'o <tytso@mit.edu>