Commit a85d2515 authored by Gabriel Krisman Bertazi's avatar Gabriel Krisman Bertazi Committed by Yongjian Sun
Browse files

ext4: fix error message when rejecting the default hash 

mainline inclusion
from mainline-v6.12-rc1
commit a2187431c395cdfbf144e3536f25468c64fc7cfa
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYR8N
CVE: CVE-2024-49968

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=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: default avatarGabriel Krisman Bertazi <krisman@suse.de>
Link: https://patch.msgid.link/87jzg1en6j.fsf_-_@mailhost.krisman.be


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Conflicts:
	fs/ext4/super.c
[Context differences.]
Signed-off-by: default avatarYongjian Sun <sunyongjian1@huawei.com>
parent 6b42706f

fs/ext4/ext4.h

+1 −0
Original line number Diff line number Diff line
@@ -2456,6 +2456,7 @@ 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)

fs/ext4/super.c

+17 −10
Original line number Diff line number Diff line
@@ -3709,13 +3709,6 @@ 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;
@@ -5234,16 +5227,27 @@ 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)
@@ -5261,6 +5265,7 @@ 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)
@@ -5408,7 +5413,9 @@ 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)