[PATCH 4.9 26/56] tipc: fix tipc_mon_delete() oops in tipc_enable_bearer() error path

Greg Kroah-Hartman
2018-03-02T08:51:12Z

From: Tommi Rantala <tommi.t.rantala@nokia.com>

[ Upstream commit 642a8439ddd8423b92f2e71960afe21ee1f66bb6 ]

Calling tipc_mon_delete() before the monitor has been created will oops.
This can happen in tipc_enable_bearer() error path if tipc_disc_create()
fails.

[ 48.589074] BUG: unable to handle kernel paging request at 0000000000001008
[ 48.590266] IP: tipc_mon_delete+0xea/0x270 [tipc]
[ 48.591223] PGD 1e60c5067 P4D 1e60c5067 PUD 1eb0cf067 PMD 0
[ 48.592230] Oops: 0000 [#1] SMP KASAN
[ 48.595610] CPU: 5 PID: 1199 Comm: tipc Tainted: G B 4.15.0-rc4-pc64-dirty #5
[ 48.597176] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
[ 48.598489] RIP: 0010:tipc_mon_delete+0xea/0x270 [tipc]
[ 48.599347] RSP: 0018:ffff8801d827f668 EFLAGS: 00010282
[ 48.600705] RAX: ffff8801ee813f00 RBX: 0000000000000204 RCX: 0000000000000000
[ 48.602183] RDX: 1ffffffff1de6a75 RSI: 0000000000000297 RDI: 0000000000000297
[ 48.604373] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff1dd1533
[ 48.605607] R10: ffffffff8eafbb05 R11: fffffbfff1dd1534 R12: 0000000000000050
[ 48.607082] R13: dead000000000200 R14: ffffffff8e73f310 R15: 0000000000001020
[ 48.608228] FS: 00007fc686484800(0000) GS:ffff8801f5540000(0000) knlGS:0000000000000000
[ 48.610189] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 48.611459] CR2: 0000000000001008 CR3: 00000001dda70002 CR4: 00000000003606e0
[ 48.612759] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 48.613831] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 48.615038] Call Trace:
[ 48.615635] tipc_enable_bearer+0x415/0x5e0 [tipc]
[ 48.620623] tipc_nl_bearer_enable+0x1ab/0x200 [tipc]
[ 48.625118] genl_family_rcv_msg+0x36b/0x570
[ 48.631233] genl_rcv_msg+0x5a/0xa0
[ 48.631867] netlink_rcv_skb+0x1cc/0x220
[ 48.636373] genl_rcv+0x24/0x40
[ 48.637306] netlink_unicast+0x29c/0x350
[ 48.639664] netlink_sendmsg+0x439/0x590
[ 48.642014] SYSC_sendto+0x199/0x250
[ 48.649912] do_syscall_64+0xfd/0x2c0
[ 48.650651] entry_SYSCALL64_slow_path+0x25/0x25
[ 48.651843] RIP: 0033:0x7fc6859848e3
[ 48.652539] RSP: 002b:00007ffd25dff938 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[ 48.654003] RAX: ffffffffffffffda RBX: 00007ffd25dff990 RCX: 00007fc6859848e3
[ 48.655303] RDX: 0000000000000054 RSI: 00007ffd25dff990 RDI: 0000000000000003
[ 48.656512] RBP: 00007ffd25dff980 R08: 00007fc685c35fc0 R09: 000000000000000c
[ 48.657697] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000d13010
[ 48.658840] R13: 00007ffd25e009c0 R14: 0000000000000000 R15: 0000000000000000
[ 48.662972] RIP: tipc_mon_delete+0xea/0x270 [tipc] RSP: ffff8801d827f668
[ 48.664073] CR2: 0000000000001008
[ 48.664576] ---[ end trace e811818d54d5ce88 ]---

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tipc/monitor.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/tipc/monitor.c
+++ b/net/tipc/monitor.c
@@ -633,9 +633,13 @@ void tipc_mon_delete(struct net *net, in
{
struct tipc_net *tn = tipc_net(net);
struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
- struct tipc_peer *self = get_self(net, bearer_id);
+ struct tipc_peer *self;
struct tipc_peer *peer, *tmp;

+ if (!mon)
+ return;
+
+ self = get_self(net, bearer_id);
write_lock_bh(&mon->lock);
tn->monitors[bearer_id] = NULL;
list_for_each_entry_safe(peer, tmp, &self->list, list) {