From: Gabriel Krisman Bertazi krisman@suse.de

commit a2187431c395cdfbf144e3536f25468c64fc7cfa upstream.

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 Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@igalia.com --- fs/ext4/ext4.h | 1 + fs/ext4/super.c | 28 +++++++++++++++++----------- 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 579c4ac511ec..27753291fb7e 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2460,6 +2460,7 @@ 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 05665f4a898c..6a2a0af0f676 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3550,14 +3550,6 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly) } #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;

@@ -5041,16 +5033,27 @@ 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) @@ -5068,6 +5071,7 @@ static void ext4_hash_info_init(struct super_block *sb) #endif } } + return 0; }

static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) @@ -5222,7 +5226,9 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb)); sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));

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

if (ext4_handle_clustersize(sb)) goto failed_mount;