The recent patch to make afs_getattr consult the server didn't account for the pseudo-inodes employed by the dynamic root-type afs superblock not having a volume or a server to access, and thus an oops occurs if such a directory is stat'd. Fix this by checking to see if the vnode->volume pointer actually points anywhere before following it in afs_getattr(). This can be tested by stat'ing a directory in /afs. It may be sufficient just to do "ls /afs" and the oops looks something like: BUG: kernel NULL pointer dereference, address: 0000000000000020 ... RIP: 0010:afs_getattr+0x8b/0x14b ... Call Trace: <TASK> vfs_statx+0x79/0xf5 vfs_fstatat+0x49/0x62
Unified · Split
| @@ -745,7 +745,8 @@ int afs_getattr(struct user_namespace *mnt_userns, const struct path *path, · 744 unmodified lines | |||
| 745 | 745 | ||
| 746 | _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation); | 746 | _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation); |
| 747 | 747 | ||
| 748 | if (!(query_flags & AT_STATX_DONT_SYNC) && | 748 | if (vnode->volume && |
| 749 | !(query_flags & AT_STATX_DONT_SYNC) && | ||
| 749 | !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { | 750 | !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { |
| 750 | key = afs_request_key(vnode->volume->cell); | 751 | key = afs_request_key(vnode->volume->cell); |
| 751 | if (IS_ERR(key)) | 752 | if (IS_ERR(key)) |