ext4: update s_journal_inum if it changes after journal replay

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[ Upstream commit 3039d8b869 ]

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>

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Baokun Li 2023-01-07 11:21:26 +08:00 • committed by Greg Kroah-Hartman

parent b4afe4629e

commit 70e66bdeae

1 changed files with 5 additions and 2 deletions

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fs/ext4/super.c

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