From: Gabriel Krisman Bertazi krisman@suse.de

[ Upstream commit a2187431c395cdfbf144e3536f25468c64fc7cfa ]

Commit 985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash") properly rejects volumes where s_def_hash_version is set to DX_HASH_SIPHASH, but the check and the error message should not look into casefold setup - a filesystem should never have DX_HASH_SIPHASH as the default hash. Fix it and, since we are there, move the check to ext4_hash_info_init.

Fixes:985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash")

Signed-off-by: Gabriel Krisman Bertazi krisman@suse.de Link: https://patch.msgid.link/87jzg1en6j.fsf_-_@mailhost.krisman.be Signed-off-by: Theodore Ts'o tytso@mit.edu [ The commit a2187431c395 intended to remove the if-block which was used for an old SIPHASH rejection check. ] Signed-off-by: Ankan Biswas spyjetfayed@gmail.com --- fs/ext4/ext4.h | 1 + fs/ext4/super.c | 20 +++++++++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 7afce7b744c0..85ba12a48f26 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2459,6 +2459,7 @@ static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize) #define DX_HASH_HALF_MD4_UNSIGNED 4 #define DX_HASH_TEA_UNSIGNED 5 #define DX_HASH_SIPHASH 6 +#define DX_HASH_LAST DX_HASH_SIPHASH

static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc, const void *address, unsigned int length) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 16a6c249580e..613f2bac439d 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5138,16 +5138,27 @@ static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb, return ret; }

-static void ext4_hash_info_init(struct super_block *sb) +static int ext4_hash_info_init(struct super_block *sb) { struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_super_block *es = sbi->s_es; unsigned int i;

+ sbi->s_def_hash_version = es->s_def_hash_version; + + if (sbi->s_def_hash_version > DX_HASH_LAST) { + ext4_msg(sb, KERN_ERR, + "Invalid default hash set in the superblock"); + return -EINVAL; + } else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) { + ext4_msg(sb, KERN_ERR, + "SIPHASH is not a valid default hash value"); + return -EINVAL; + } + for (i = 0; i < 4; i++) sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);

- sbi->s_def_hash_version = es->s_def_hash_version; if (ext4_has_feature_dir_index(sb)) { i = le32_to_cpu(es->s_flags); if (i & EXT2_FLAGS_UNSIGNED_HASH) @@ -5165,6 +5176,7 @@ static void ext4_hash_info_init(struct super_block *sb) #endif } } + return 0; }

static int ext4_block_group_meta_init(struct super_block *sb, int silent) @@ -5309,7 +5321,9 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) if (err) goto failed_mount;

- ext4_hash_info_init(sb); + err = ext4_hash_info_init(sb); + if (err) + goto failed_mount;

err = ext4_handle_clustersize(sb); if (err)