vcan0: j1939_tp_rxtimer: 0x0000000030363506: abort rx timeout. Force session deactivation ================================================================== BUG: KASAN: use-after-free in __run_hrtimer kernel/time/hrtimer.c:1521 [inline] BUG: KASAN: use-after-free in __hrtimer_run_queues+0xe18/0xf10 kernel/time/hrtimer.c:1583 Read of size 1 at addr ffff888057674973 by task kworker/u4:11/26204 CPU: 0 PID: 26204 Comm: kworker/u4:11 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:641 __run_hrtimer kernel/time/hrtimer.c:1521 [inline] __hrtimer_run_queues+0xe18/0xf10 kernel/time/hrtimer.c:1583 hrtimer_run_softirq+0x16d/0x250 kernel/time/hrtimer.c:1600 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x192/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1140 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:check_kcov_mode kernel/kcov.c:153 [inline] RIP: 0010:write_comp_data+0x10/0x70 kernel/kcov.c:208 Code: 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 c3 0f 1f 84 00 00 00 00 00 65 4c 8b 04 25 00 1f 02 00 65 8b 05 08 35 8f 7e 00 01 1f 00 75 51 41 8b 80 d0 13 00 00 83 f8 03 75 45 49 8b 80 RSP: 0018:ffffc900052f7cc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000080000000 RBX: ffff8880a7219d40 RCX: ffffffff87a5e82f RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff888059888c00 R08: ffff888088032200 R09: ffffed1015cc70f4 R10: ffffed1015cc70f3 R11: ffff8880ae63879b R12: 0000000000000001 R13: 00000000000003b8 R14: dffffc0000000000 R15: ffff88808dcd9dc0 rcu_read_lock include/linux/rcupdate.h:602 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0x4cf/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x965/0x16a0 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 29351: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] j1939_session_new+0x7c/0x3f0 net/can/j1939/transport.c:1418 j1939_tp_send+0x22f/0x800 net/can/j1939/transport.c:1877 j1939_sk_send_loop net/can/j1939/socket.c:1037 [inline] j1939_sk_sendmsg+0xabf/0x1360 net/can/j1939/socket.c:1160 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x308/0x7e0 net/socket.c:2362 ___sys_sendmsg+0x100/0x170 net/socket.c:2416 __sys_sendmmsg+0x195/0x480 net/socket.c:2506 __do_sys_sendmmsg net/socket.c:2535 [inline] __se_sys_sendmmsg net/socket.c:2532 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2532 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 26204: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:476 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 j1939_session_destroy net/can/j1939/transport.c:276 [inline] __j1939_session_release net/can/j1939/transport.c:284 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put+0x25c/0x330 net/can/j1939/transport.c:289 j1939_tp_rxtimer+0x2e9/0x2f4 net/can/j1939/transport.c:1194 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x3a2/0xf10 kernel/time/hrtimer.c:1583 hrtimer_run_softirq+0x16d/0x250 kernel/time/hrtimer.c:1600 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292 The buggy address belongs to the object at ffff888057674800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 371 bytes inside of 512-byte region [ffff888057674800, ffff888057674a00) The buggy address belongs to the page: page:ffffea00015d9d00 refcount:1 mapcount:0 mapping:ffff8880aa000a80 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000220c048 ffffea0002207548 ffff8880aa000a80 raw: 0000000000000000 ffff888057674000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888057674800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057674880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888057674900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888057674980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057674a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================