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| author | Ojaswin Mujoo <ojaswin@linux.ibm.com> | 2025-03-28 11:54:52 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:51:00 +0200 |
| commit | a8550ac19d46de531b2de784fcaad860fa49aa6e (patch) | |
| tree | 4aa458d1000ce981cb5e8cc6e9090d8b15edabc7 /fs | |
| parent | ea92c93887f500c2298f5c8b135a68929b664d85 (diff) | |
| download | linux-a8550ac19d46de531b2de784fcaad860fa49aa6e.tar.gz linux-a8550ac19d46de531b2de784fcaad860fa49aa6e.tar.bz2 linux-a8550ac19d46de531b2de784fcaad860fa49aa6e.zip | |
ext4: make block validity check resistent to sb bh corruption
[ Upstream commit ccad447a3d331a239477c281533bacb585b54a98 ]
Block validity checks need to be skipped in case they are called
for journal blocks since they are part of system's protected
zone.
Currently, this is done by checking inode->ino against
sbi->s_es->s_journal_inum, which is a direct read from the ext4 sb
buffer head. If someone modifies this underneath us then the
s_journal_inum field might get corrupted. To prevent against this,
change the check to directly compare the inode with journal->j_inode.
**Slight change in behavior**: During journal init path,
check_block_validity etc might be called for journal inode when
sbi->s_journal is not set yet. In this case we now proceed with
ext4_inode_block_valid() instead of returning early. Since systems zones
have not been set yet, it is okay to proceed so we can perform basic
checks on the blocks.
Suggested-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/0c06bc9ebfcd6ccfed84a36e79147bf45ff5adc1.1743142920.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/block_validity.c | 5 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 7 |
2 files changed, 6 insertions, 6 deletions
diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c index 6fe3c941b565..4d6ba140276b 100644 --- a/fs/ext4/block_validity.c +++ b/fs/ext4/block_validity.c @@ -351,10 +351,9 @@ int ext4_check_blockref(const char *function, unsigned int line, { __le32 *bref = p; unsigned int blk; + journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; - if (ext4_has_feature_journal(inode->i_sb) && - (inode->i_ino == - le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum))) + if (journal && inode == journal->j_inode) return 0; while (bref < p+max) { diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index ddfeaf19bff1..f2b60fb0b937 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -378,10 +378,11 @@ static int __check_block_validity(struct inode *inode, const char *func, unsigned int line, struct ext4_map_blocks *map) { - if (ext4_has_feature_journal(inode->i_sb) && - (inode->i_ino == - le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum))) + journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + + if (journal && inode == journal->j_inode) return 0; + if (!ext4_inode_block_valid(inode, map->m_pblk, map->m_len)) { ext4_error_inode(inode, func, line, map->m_pblk, "lblock %lu mapped to illegal pblock %llu " |