Patch "ext4: ext4_search_dir should return a proper error" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ext4: ext4_search_dir should return a proper error

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ext4-ext4_search_dir-should-return-a-proper-error.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 36b2e772eec837c41898c50e5bc1519aa02dc7ef
Author: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxx>
Date:   Wed Aug 21 12:23:21 2024 -0300

    ext4: ext4_search_dir should return a proper error
    
    [ Upstream commit cd69f8f9de280e331c9e6ff689ced0a688a9ce8f ]
    
    ext4_search_dir currently returns -1 in case of a failure, while it returns
    0 when the name is not found. In such failure cases, it should return an
    error code instead.
    
    This becomes even more important when ext4_find_inline_entry returns an
    error code as well in the next commit.
    
    -EFSCORRUPTED seems appropriate as such error code as these failures would
    be caused by unexpected record lengths and is in line with other instances
    of ext4_check_dir_entry failures.
    
    In the case of ext4_dx_find_entry, the current use of ERR_BAD_DX_DIR was
    left as is to reduce the risk of regressions.
    
    Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxx>
    Link: https://patch.msgid.link/20240821152324.3621860-2-cascardo@xxxxxxxxxx
    Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 3bd2301cb48e7..9913aa37e697c 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1526,7 +1526,7 @@ static bool ext4_match(struct inode *parent,
 }
 
 /*
- * Returns 0 if not found, -1 on failure, and 1 on success
+ * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success
  */
 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 		    struct inode *dir, struct ext4_filename *fname,
@@ -1547,7 +1547,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 			 * a full check */
 			if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
 						 buf_size, offset))
-				return -1;
+				return -EFSCORRUPTED;
 			*res_dir = de;
 			return 1;
 		}
@@ -1555,7 +1555,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 		de_len = ext4_rec_len_from_disk(de->rec_len,
 						dir->i_sb->s_blocksize);
 		if (de_len <= 0)
-			return -1;
+			return -EFSCORRUPTED;
 		offset += de_len;
 		de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
 	}
@@ -1707,8 +1707,10 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
 			goto cleanup_and_exit;
 		} else {
 			brelse(bh);
-			if (i < 0)
+			if (i < 0) {
+				ret = ERR_PTR(i);
 				goto cleanup_and_exit;
+			}
 		}
 	next:
 		if (++block >= nblocks)
@@ -1803,7 +1805,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 		if (retval == 1)
 			goto success;
 		brelse(bh);
-		if (retval == -1) {
+		if (retval < 0) {
 			bh = ERR_PTR(ERR_BAD_DX_DIR);
 			goto errout;
 		}