[PATCH AUTOSEL 6.11 18/76] ext4: filesystems without casefold feature cannot be mounted with siphash

Sasha Levin
2024-10-04T18:19:00Z

From: Lizhi Xu <lizhi.xu@windriver.com>

[ Upstream commit 985b67cd86392310d9e9326de941c22fc9340eec ]

When mounting the ext4 filesystem, if the default hash version is set to
DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.

Reported-by: syzbot+340581ba9dceb7e06fb3@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Link: https://patch.msgid.link/20240605012335.44086-1-lizhi.xu@windriver.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext4/super.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 93c016b186c07..e8e32cf3e2228 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3583,6 +3583,13 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
"mounted without CONFIG_UNICODE");
return 0;
}
+ if (EXT4_SB(sb)->s_es->s_def_hash_version == DX_HASH_SIPHASH &&
+ !ext4_has_feature_casefold(sb)) {
+ ext4_msg(sb, KERN_ERR,
+ "Filesystem without casefold feature cannot be "
+ "mounted with siphash");
+ return 0;
+ }

if (readonly)
return 1;
--
2.43.0