In the Linux kernel, the following vulnerability has been resolved:

can: j1939: Fix UAF in j1939_sk_match_filter during setsockopt(SO_J1939_FILTER)

Lock jsk->sk to prevent UAF when setsockopt(..., SO_J1939_FILTER, ...) modifies jsk->filters while receiving packets.

Following trace was seen on affected system:

BUG: KASAN: slab-use-after-free in j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] Read of size 4 at addr ffff888012144014 by task j1939/350

CPU: 0 PID: 350 Comm: j1939 Tainted: G W OE 6.5.0-rc5 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: print_report+0xd3/0x620 ? kasan_complete_mode_report_info+0x7d/0x200 ? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] kasan_report+0xc2/0x100 ? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] __asan_load4+0x84/0xb0 j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] j1939_sk_recv+0x20b/0x320 [can_j1939] ? __kasan_check_write+0x18/0x20 ? __pfx_j1939_sk_recv+0x10/0x10 [can_j1939] ? j1939_simple_recv+0x69/0x280 [can_j1939] ? j1939_ac_recv+0x5e/0x310 [can_j1939] j1939_can_recv+0x43f/0x580 [can_j1939] ? __pfx_j1939_can_recv+0x10/0x10 [can_j1939] ? raw_rcv+0x42/0x3c0 [can_raw] ? __pfx_j1939_can_recv+0x10/0x10 [can_j1939] can_rcv_filter+0x11f/0x350 [can] can_receive+0x12f/0x190 [can] ? __pfx_can_rcv+0x10/0x10 [can] can_rcv+0xdd/0x130 [can] ? __pfx_can_rcv+0x10/0x10 [can] __netif_receive_skb_one_core+0x13d/0x150 ? __pfx___netif_receive_skb_one_core+0x10/0x10 ? __kasan_check_write+0x18/0x20 ? _raw_spin_lock_irq+0x8c/0xe0 __netif_receive_skb+0x23/0xb0 process_backlog+0x107/0x260 __napi_poll+0x69/0x310 net_rx_action+0x2a1/0x580 ? __pfx_net_rx_action+0x10/0x10 ? __pfx__raw_spin_lock+0x10/0x10 ? handle_irq_event+0x7d/0xa0 __do_softirq+0xf3/0x3f8 do_softirq+0x53/0x80 </IRQ> <TASK> __local_bh_enable_ip+0x6e/0x70...