This is a note to let you know that I've just added the patch titled reiserfs: Fix oops during mount to the 5.9-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: reiserfs-fix-oops-during-mount.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c2bb80b8bdd04dfe32364b78b61b6a47f717af52 Mon Sep 17 00:00:00 2001 From: Jan Kara <jack@xxxxxxx> Date: Wed, 30 Sep 2020 17:08:20 +0200 Subject: reiserfs: Fix oops during mount From: Jan Kara <jack@xxxxxxx> commit c2bb80b8bdd04dfe32364b78b61b6a47f717af52 upstream. With suitably crafted reiserfs image and mount command reiserfs will crash when trying to verify that XATTR_ROOT directory can be looked up in / as that recurses back to xattr code like: xattr_lookup+0x24/0x280 fs/reiserfs/xattr.c:395 reiserfs_xattr_get+0x89/0x540 fs/reiserfs/xattr.c:677 reiserfs_get_acl+0x63/0x690 fs/reiserfs/xattr_acl.c:209 get_acl+0x152/0x2e0 fs/posix_acl.c:141 check_acl fs/namei.c:277 [inline] acl_permission_check fs/namei.c:309 [inline] generic_permission+0x2ba/0x550 fs/namei.c:353 do_inode_permission fs/namei.c:398 [inline] inode_permission+0x234/0x4a0 fs/namei.c:463 lookup_one_len+0xa6/0x200 fs/namei.c:2557 reiserfs_lookup_privroot+0x85/0x1e0 fs/reiserfs/xattr.c:972 reiserfs_fill_super+0x2b51/0x3240 fs/reiserfs/super.c:2176 mount_bdev+0x24f/0x360 fs/super.c:1417 Fix the problem by bailing from reiserfs_xattr_get() when xattrs are not yet initialized. CC: stable@xxxxxxxxxxxxxxx Reported-by: syzbot+9b33c9b118d77ff59b6f@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/reiserfs/xattr.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -674,6 +674,13 @@ reiserfs_xattr_get(struct inode *inode, if (get_inode_sd_version(inode) == STAT_DATA_V1) return -EOPNOTSUPP; + /* + * priv_root needn't be initialized during mount so allow initial + * lookups to succeed. + */ + if (!REISERFS_SB(inode->i_sb)->priv_root) + return 0; + dentry = xattr_lookup(inode, name, XATTR_REPLACE); if (IS_ERR(dentry)) { err = PTR_ERR(dentry); Patches currently in stable-queue which might be from jack@xxxxxxx are queue-5.9/reiserfs-initialize-inode-keys-properly.patch queue-5.9/reiserfs-fix-oops-during-mount.patch