This is a note to let you know that I've just added the patch titled jfs: prevent NULL deref in diFree to the 5.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: jfs-prevent-null-deref-in-difree.patch and it can be found in the queue-5.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f2d32429b917a646b870c296f791ce3eb3098467 Author: Haimin Zhang <tcs_kernel@xxxxxxxxxxx> Date: Tue Mar 22 21:59:17 2022 +0800 jfs: prevent NULL deref in diFree [ Upstream commit a53046291020ec41e09181396c1e829287b48d47 ] Add validation check for JFS_IP(ipimap)->i_imap to prevent a NULL deref in diFree since diFree uses it without do any validations. When function jfs_mount calls diMount to initialize fileset inode allocation map, it can fail and JFS_IP(ipimap)->i_imap won't be initialized. Then it calls diFreeSpecial to close fileset inode allocation map inode and it will flow into jfs_evict_inode. Function jfs_evict_inode just validates JFS_SBI(inode->i_sb)->ipimap, then calls diFree. diFree use JFS_IP(ipimap)->i_imap directly, then it will cause a NULL deref. Reported-by: TCS Robot <tcs_robot@xxxxxxxxxxx> Signed-off-by: Haimin Zhang <tcs_kernel@xxxxxxxxxxx> Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c index 57ab424c05ff..072821b50ab9 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -146,12 +146,13 @@ void jfs_evict_inode(struct inode *inode) dquot_initialize(inode); if (JFS_IP(inode)->fileset == FILESYSTEM_I) { + struct inode *ipimap = JFS_SBI(inode->i_sb)->ipimap; truncate_inode_pages_final(&inode->i_data); if (test_cflag(COMMIT_Freewmap, inode)) jfs_free_zero_link(inode); - if (JFS_SBI(inode->i_sb)->ipimap) + if (ipimap && JFS_IP(ipimap)->i_imap) diFree(inode); /*