From: Haimin Zhang <tcs_kernel@xxxxxxxxxxx>
If root_inode->i_op is reiserfs_special_inode_operations
reiserfs_special_inode_operations doesn't implement the lookup callback
function,resulting an NULL pointer when the reiserfs_lookup_privroot()
function was called.
Call Trace:
__lookup_slow+0x267/0x490 build/../fs/namei.c:1646
lookup_one_len+0x163/0x190 build/../fs/namei.c:2663
reiserfs_lookup_privroot+0x92/0x290 build/../fs/reiserfs/xattr.c:980
reiserfs_fill_super+0x1f2a/0x2d80 build/../fs/reiserfs/super.c:2176
mount_bdev+0x33d/0x410 build/../fs/super.c:1368
legacy_get_tree+0x103/0x210 build/../fs/fs_context.c:610
vfs_get_tree+0x86/0x2f0 build/../fs/super.c:1498
do_new_mount build/../fs/namespace.c:2905 [inline]
path_mount+0x688/0x1d10 build/../fs/namespace.c:3235
do_mount+0xf1/0x110 build/../fs/namespace.c:3248
__do_sys_mount build/../fs/namespace.c:3456 [inline]
__se_sys_mount build/../fs/namespace.c:3433 [inline]
__x64_sys_mount+0x1d5/0x220 build/../fs/namespace.c:3433
do_syscall_x64 build/../arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x34/0xb0 build/../arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Reported-by: syzbot+11c49c...@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Haimin Zhang <tcs_kernel@xxxxxxxxxxx>
---
fs/reiserfs/namei.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index 3d7a35d..947b51b 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -350,6 +350,12 @@ static int reiserfs_find_entry(struct inode *dir, const char *name, int namelen,
} /* while (1) */
}
+static struct dentry *reiserfs_noop_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ return ERR_PTR(-ENOENT);
+}
+
static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
@@ -1680,6 +1686,7 @@ static int reiserfs_rename(struct user_namespace *mnt_userns,
* special file operations.. just xattr/acl stuff
*/
const struct inode_operations reiserfs_special_inode_operations = {
+ .lookup = reiserfs_noop_lookup,
.setattr = reiserfs_setattr,
.listxattr = reiserfs_listxattr,
.permission = reiserfs_permission,
--
1.8.3.1
