From: Ojaswin Mujoo ojaswin@linux.ibm.com
[ 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... Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/block_validity.c | 5 ++--- 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 6fe3c941b5651..4d6ba140276b5 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 19d7bcf16ebb8..731660bf2203e 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 "