samsung_sm8750/android_kernel_samsung_sm8750
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ext4: make block validity check resistent to sb bh corruption

Browse Source 
[ 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>
This commit is contained in:
Ojaswin Mujoo
2025-03-28 11:54:52 +05:30
committed by Greg Kroah-Hartman
parent ea92c93887
commit a8550ac19d
2 changed files with 6 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
fs/ext4/block_validity.c
View File

@@ -351,10 +351,9 @@ int ext4_check_blockref(const char *function, unsigned int line,
{ {
__le32 *bref = p; __le32 *bref = p;
unsigned int blk; unsigned int blk;
journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
if (ext4_has_feature_journal(inode->i_sb) && if (journal && inode == journal->j_inode)
(inode->i_ino ==
le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum)))
return 0; return 0;
while (bref < p+max) { while (bref < p+max) {

7
fs/ext4/inode.c
View File

@@ -378,10 +378,11 @@ static int __check_block_validity(struct inode *inode, const char *func,
unsigned int line, unsigned int line,
struct ext4_map_blocks *map) struct ext4_map_blocks *map)
{ {
if (ext4_has_feature_journal(inode->i_sb) && journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
(inode->i_ino ==
le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum))) if (journal && inode == journal->j_inode)
return 0; return 0;
if (!ext4_inode_block_valid(inode, map->m_pblk, map->m_len)) { if (!ext4_inode_block_valid(inode, map->m_pblk, map->m_len)) {
ext4_error_inode(inode, func, line, map->m_pblk, ext4_error_inode(inode, func, line, map->m_pblk,
"lblock %lu mapped to illegal pblock %llu " "lblock %lu mapped to illegal pblock %llu "