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| author | Baokun Li <libaokun1@huawei.com> | 2022-10-26 07:23:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-07 13:11:58 +0300 |
| commit | 488a5c2bf7543c3cd3f07a025f2e62be91599430 (patch) | |
| tree | 2be9b014ad15e1af49059297c891c6cb3738eab4 /fs/ext4/inode.c | |
| parent | 7753d6657873a2523a9989e6c09090cd503bbcda (diff) | |
| download | linux-488a5c2bf7543c3cd3f07a025f2e62be91599430.tar.xz | |
ext4: add EXT4_IGET_BAD flag to prevent unexpected bad inode
commit 63b1e9bccb71fe7d7e3ddc9877dbdc85e5d2d023 upstream.
There are many places that will get unhappy (and crash) when ext4_iget()
returns a bad inode. However, if iget the boot loader inode, allows a bad
inode to be returned, because the inode may not be initialized. This
mechanism can be used to bypass some checks and cause panic. To solve this
problem, we add a special iget flag EXT4_IGET_BAD. Only with this flag
we'd be returning bad inode from ext4_iget(), otherwise we always return
the error code if the inode is bad inode.(suggested by Jan Kara)
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20221026042310.3839669-4-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4/inode.c')
| -rw-r--r-- | fs/ext4/inode.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index bd989e61333a..f53c67909af5 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5053,8 +5053,14 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, if (IS_CASEFOLDED(inode) && !ext4_has_feature_casefold(inode->i_sb)) ext4_error_inode(inode, function, line, 0, "casefold flag without casefold feature"); - brelse(iloc.bh); + if (is_bad_inode(inode) && !(flags & EXT4_IGET_BAD)) { + ext4_error_inode(inode, function, line, 0, + "bad inode without EXT4_IGET_BAD flag"); + ret = -EUCLEAN; + goto bad_inode; + } + brelse(iloc.bh); unlock_new_inode(inode); return inode; |