From 63b1e9bccb71fe7d7e3ddc9877dbdc85e5d2d023 Mon Sep 17 00:00:00 2001 From: Baokun Li Date: Wed, 26 Oct 2022 12:23:09 +0800 Subject: ext4: add EXT4_IGET_BAD flag to prevent unexpected bad inode 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 Reviewed-by: Jason Yan Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20221026042310.3839669-4-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org --- fs/ext4/ioctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/ext4/ioctl.c') diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 95dfea28bf4e..9ed7b9fe2132 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -374,7 +374,8 @@ static long swap_inode_boot_loader(struct super_block *sb, blkcnt_t blocks; unsigned short bytes; - inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, EXT4_IGET_SPECIAL); + inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, + EXT4_IGET_SPECIAL | EXT4_IGET_BAD); if (IS_ERR(inode_bl)) return PTR_ERR(inode_bl); ei_bl = EXT4_I(inode_bl); -- cgit v1.2.3-70-g09d2