diff options
| author | Baokun Li <[email protected]> | 2023-01-07 11:21:26 +0800 |
|---|---|---|
| committer | Theodore Ts'o <[email protected]> | 2023-02-19 00:09:59 -0500 |
| commit | 3039d8b8692408438a618fac2776b629852663c3 (patch) | |
| tree | 0a5ecb12895f89ed755e48f90a8ff0f3e2f39802 | |
| parent | 5cd740287ae5e3f9d1c46f5bfe8778972fd6d3fe (diff) | |
ext4: update s_journal_inum if it changes after journal replay
When mounting a crafted ext4 image, s_journal_inum may change after journal
replay, which is obviously unreasonable because we have successfully loaded
and replayed the journal through the old s_journal_inum. And the new
s_journal_inum bypasses some of the checks in ext4_get_journal(), which
may trigger a null pointer dereference problem. So if s_journal_inum
changes after the journal replay, we ignore the change, and rewrite the
current journal_inum to the superblock.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216541
Reported-by: Luís Henriques <[email protected]>
Signed-off-by: Baokun Li <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
| -rw-r--r-- | fs/ext4/super.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 3b9e30e1afd9..45bcfd35e559 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5953,8 +5953,11 @@ static int ext4_load_journal(struct super_block *sb, if (!really_read_only && journal_devnum && journal_devnum != le32_to_cpu(es->s_journal_dev)) { es->s_journal_dev = cpu_to_le32(journal_devnum); - - /* Make sure we flush the recovery flag to disk. */ + ext4_commit_super(sb); + } + if (!really_read_only && journal_inum && + journal_inum != le32_to_cpu(es->s_journal_inum)) { + es->s_journal_inum = cpu_to_le32(journal_inum); ext4_commit_super(sb); } |