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authorBaokun Li <libaokun1@huawei.com>2023-01-07 06:21:26 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-22 15:33:54 +0300
commit70e66bdeae4d0f7c8e87762f425b68aedd5e8955 (patch)
tree8f5c2e5b654d1c7d36bfd4f018b0151ec6bead83 /fs/ext4
parentb4afe4629ec8f7d740617866e4286717a1c9c4c3 (diff)
downloadlinux-70e66bdeae4d0f7c8e87762f425b68aedd5e8955.tar.xz
ext4: update s_journal_inum if it changes after journal replay
[ Upstream commit 3039d8b8692408438a618fac2776b629852663c3 ] 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 <lhenriques@suse.de> Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230107032126.4165860-3-libaokun1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/super.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 801160099958..2528e8216c33 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5967,8 +5967,11 @@ 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);
}