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authorMarc Dionne <marc.dionne@auristor.com>2019-01-09 17:23:54 +0000
committerDavid Howells <dhowells@redhat.com>2019-01-17 15:15:52 +0000
commit4882a27cec24319d10f95e978ecc80050e3e3e15 (patch)
treea3467dbac70cbd71e0a3c4fe292c32086e48fc22
parent5edc22cc1d33d6a88d175d25adc38d2a5cee134d (diff)
downloadlinux-4882a27cec24319d10f95e978ecc80050e3e3e15.tar.bz2
afs: Don't set vnode->cb_s_break in afs_validate()
A cb_interest record is not necessarily attached to the vnode on entry to afs_validate(), which can cause an oops when we try to bring the vnode's cb_s_break up to date in the default case (ie. no current callback promise and the vnode has not been deleted). Fix this by simply removing the line, as vnode->cb_s_break will be set when needed by afs_register_server_cb_interest() when we next get a callback promise from RPC call. The oops looks something like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 ... RIP: 0010:afs_validate+0x66/0x250 [kafs] ... Call Trace: afs_d_revalidate+0x8d/0x340 [kafs] ? __d_lookup+0x61/0x150 lookup_dcache+0x44/0x70 ? lookup_dcache+0x44/0x70 __lookup_hash+0x24/0xa0 do_unlinkat+0x11d/0x2c0 __x64_sys_unlink+0x23/0x30 do_syscall_64+0x4d/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: ae3b7361dc0e ("afs: Fix validation/callback interaction") Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
-rw-r--r--fs/afs/inode.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 6b17d3620414..211343831c30 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -414,7 +414,6 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
valid = true;
} else {
- vnode->cb_s_break = vnode->cb_interest->server->cb_s_break;
vnode->cb_v_break = vnode->volume->cb_v_break;
valid = false;
}