From: Thadeu Lima de Souza Cascardo cascardo@igalia.com

mainline inclusion from mainline-v6.12-rc1 commit cd69f8f9de280e331c9e6ff689ced0a688a9ce8f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYPK6 CVE: CVE-2024-47701

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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@igalia.com Link: https://patch.msgid.link/20240821152324.3621860-2-cascardo@igalia.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Baokun Li libaokun1@huawei.com --- fs/ext4/namei.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 3bd2301cb48e..9913aa37e697 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; }