vcan0: j1939_tp_rxtimer: 0x0000000086ad42d2: 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 ffff888047a02173 by task kworker/u4:10/26183 CPU: 0 PID: 26183 Comm: kworker/u4:10 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 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq.part.0+0x10f/0x160 kernel/softirq.c:337 do_softirq kernel/softirq.c:329 [inline] __local_bh_enable_ip+0x20e/0x270 kernel/softirq.c:189 spin_unlock_bh include/linux/spinlock.h:398 [inline] batadv_nc_purge_paths+0x264/0x380 net/batman-adv/network-coding.c:470 batadv_nc_worker+0x2c6/0x760 net/batman-adv/network-coding.c:721 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 4891: 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 26183: 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 ffff888047a02000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 371 bytes inside of 512-byte region [ffff888047a02000, ffff888047a02200) The buggy address belongs to the page: page:ffffea00011e8080 refcount:1 mapcount:0 mapping:ffff8880aa000a80 index:0xffff888047a02800 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00026aca48 ffffea0002931a08 ffff8880aa000a80 raw: ffff888047a02800 ffff888047a02000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888047a02000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888047a02080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888047a02100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888047a02180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888047a02200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================