syzbot reports that a recent fix causes nesting issues between the (now)
raw timeoutlock and the eventfd locking:

=============================
[ BUG: Invalid wait context ]
6.13.0-rc4-00080-g9828a4c0901f #29 Not tainted
-----------------------------
kworker/u32:0/68094 is trying to lock:
ffff000014d7a520 (&ctx->wqh#2){..-.}-{3:3}, at: eventfd_signal_mask+0x64/0x180
other info that might help us debug this:
context-{5:5}
6 locks held by kworker/u32:0/68094:
 #0: ffff0000c1d98148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x4e8/0xfc0
 #1: ffff80008d927c78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x53c/0xfc0
 #2: ffff0000c59bc3d8 (&ctx->completion_lock){+.+.}-{3:3}, at: io_kill_timeouts+0x40/0x180
 #3: ffff0000c59bc358 (&ctx->timeout_lock){-.-.}-{2:2}, at: io_kill_timeouts+0x48/0x180
 #4: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
 #5: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
stack backtrace:
CPU: 7 UID: 0 PID: 68094 Comm: kworker/u32:0 Not tainted 6.13.0-rc4-00080-g9828a4c0901f #29
Hardware name: linux,dummy-virt (DT)
Workqueue: iou_exit io_ring_exit_work
Call trace:
 show_stack+0x1c/0x30 (C)
 __dump_stack+0x24/0x30
 dump_stack_lvl+0x60/0x80
 dump_stack+0x14/0x20
 __lock_acquire+0x19f8/0x60c8
 lock_acquire+0x1a4/0x540
 _raw_spin_lock_irqsave+0x90/0xd0
 eventfd_signal_mask+0x64/0x180
 io_eventfd_signal+0x64/0x108
 io_req_local_work_add+0x294/0x430
 __io_req_task_work_add+0x1c0/0x270
 io_kill_timeout+0x1f0/0x288
 io_kill_timeouts+0xd4/0x180
 io_uring_try_cancel_requests+0x2e8/0x388
 io_ring_exit_work+0x150/0x550
 process_one_work+0x5e8/0xfc0
 worker_thread+0x7ec/0xc80
 kthread+0x24c/0x300
 ret_from_fork+0x10/0x20

because after the preempt-rt fix for the timeout lock nesting inside
the io-wq lock, we now have the eventfd spinlock nesting inside the
raw timeout spinlock.

Rather than play whack-a-mole with other nesting on the timeout lock,
split the deletion and killing of timeouts so queueing the task_work
for the timeout cancelations can get done outside of the timeout lock.

Reported-by: [email protected]
Fixes: 020b40f ("io_uring: make ctx->timeout_lock a raw spinlock")
Signed-off-by: Jens Axboe <[email protected]>

KMSAN reported an uninit-value access in vxlan_vnifilter_dump() [1].

If the length of the netlink message payload is less than
sizeof(struct tunnel_msg), vxlan_vnifilter_dump() accesses bytes
beyond the message. This can lead to uninit-value access. Fix this by
returning an error in such situations.

[1]
BUG: KMSAN: uninit-value in vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
 vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
 rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6786
 netlink_dump+0x93e/0x15f0 net/netlink/af_netlink.c:2317
 __netlink_dump_start+0x716/0xd60 net/netlink/af_netlink.c:2432
 netlink_dump_start include/linux/netlink.h:340 [inline]
 rtnetlink_dump_start net/core/rtnetlink.c:6815 [inline]
 rtnetlink_rcv_msg+0x1256/0x14a0 net/core/rtnetlink.c:6882
 netlink_rcv_skb+0x467/0x660 net/netlink/af_netlink.c:2542
 rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6944
 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
 netlink_unicast+0xed6/0x1290 net/netlink/af_netlink.c:1347
 netlink_sendmsg+0x1092/0x1230 net/netlink/af_netlink.c:1891
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x330/0x3d0 net/socket.c:726
 ____sys_sendmsg+0x7f4/0xb50 net/socket.c:2583
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2637
 __sys_sendmsg net/socket.c:2669 [inline]
 __do_sys_sendmsg net/socket.c:2674 [inline]
 __se_sys_sendmsg net/socket.c:2672 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2672
 x64_sys_call+0x3878/0x3d90 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4110 [inline]
 slab_alloc_node mm/slub.c:4153 [inline]
 kmem_cache_alloc_node_noprof+0x800/0xe80 mm/slub.c:4205
 kmalloc_reserve+0x13b/0x4b0 net/core/skbuff.c:587
 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1323 [inline]
 netlink_alloc_large_skb+0xa5/0x280 net/netlink/af_netlink.c:1196
 netlink_sendmsg+0xac9/0x1230 net/netlink/af_netlink.c:1866
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x330/0x3d0 net/socket.c:726
 ____sys_sendmsg+0x7f4/0xb50 net/socket.c:2583
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2637
 __sys_sendmsg net/socket.c:2669 [inline]
 __do_sys_sendmsg net/socket.c:2674 [inline]
 __se_sys_sendmsg net/socket.c:2672 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2672
 x64_sys_call+0x3878/0x3d90 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 30991 Comm: syz.4.10630 Not tainted 6.12.0-10694-gc44daa7e3c73 #29
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014

Fixes: f9c4bb0 ("vxlan: vni filtering support on collect metadata device")
Reported-by: syzkaller <[email protected]>
Signed-off-by: Shigeru Yoshida <[email protected]>
Reviewed-by: Ido Schimmel <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>