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: Rajani Kantha rajanikantha@engineer.com --- fs/ext4/super.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 71ced0ada9a2..7522bd019639 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3626,6 +3626,13 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly) return 0; } #endif + 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; -- 2.35.3