================================================================== BUG: KASAN: use-after-free in dev_map_flush_old kernel/bpf/devmap.c:389 [inline] BUG: KASAN: use-after-free in __dev_map_entry_free+0x2ab/0x300 kernel/bpf/devmap.c:403 Read of size 8 at addr ffff8801b4bd8648 by task kworker/0:4/6526 CPU: 0 PID: 6526 Comm: kworker/0:4 Not tainted 4.20.0-rc1-next-20181109+ #110 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: rcu_gp process_srcu Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 dev_map_flush_old kernel/bpf/devmap.c:389 [inline] __dev_map_entry_free+0x2ab/0x300 kernel/bpf/devmap.c:403 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0xc57/0x15f0 kernel/rcu/tree.c:2754 __do_softirq+0x308/0xb7e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1061 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804 RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:76 [inline] RIP: 0010:preempt_count_add+0x6b/0x1b0 kernel/sched/core.c:3188 Code: 85 c9 75 07 65 8b 05 74 31 ac 7e 48 b8 00 00 00 00 00 fc ff df 48 89 da 83 e3 07 48 c1 ea 03 83 c3 03 65 44 01 25 55 31 ac 7e <0f> b6 04 02 38 c3 7c 08 84 c0 0f 85 01 01 00 00 8b 15 0f 6b b8 09 RSP: 0018:ffff88017d26f2d0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 1ffffffff161c4f4 RSI: ffffffff83920668 RDI: 0000000000000001 RBP: ffff88017d26f2e0 R08: ffff8801bc7ba480 R09: 1ffffd1ffffa0d80 R10: ffff88017d26f418 R11: ffffffff8b102267 R12: 0000000000000001 R13: 0000000000002ced R14: 0000000000000000 R15: ffffffff8b101ec0 delay_tsc+0x3d/0xc0 arch/x86/lib/delay.c:68 __delay arch/x86/lib/delay.c:161 [inline] __const_udelay+0x62/0x80 arch/x86/lib/delay.c:175 try_check_zero+0x384/0x5f0 kernel/rcu/srcutree.c:730 QAT: Invalid ioctl srcu_advance_state kernel/rcu/srcutree.c:1167 [inline] process_srcu+0x641/0x980 kernel/rcu/srcutree.c:1261 process_one_work+0xc8b/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Allocated by task 26789: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 kmalloc include/linux/slab.h:546 [inline] kzalloc include/linux/slab.h:741 [inline] dev_map_alloc+0x210/0x800 kernel/bpf/devmap.c:102 find_and_alloc_map kernel/bpf/syscall.c:129 [inline] map_create+0x3bd/0x1110 kernel/bpf/syscall.c:509 __do_sys_bpf kernel/bpf/syscall.c:2489 [inline] __se_sys_bpf kernel/bpf/syscall.c:2466 [inline] __x64_sys_bpf+0x303/0x520 kernel/bpf/syscall.c:2466 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2885: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 dev_map_free+0x514/0x690 kernel/bpf/devmap.c:192 bpf_map_free_deferred+0xd9/0x110 kernel/bpf/syscall.c:290 process_one_work+0xc8b/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8801b4bd8540 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff8801b4bd8540, ffff8801b4bd8740) The buggy address belongs to the page: page:ffffea0006d2f600 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0006d7ddc8 ffffea000745fa08 ffff8801da800940 raw: 0000000000000000 ffff8801b4bd8040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b4bd8500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801b4bd8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801b4bd8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801b4bd8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b4bd8700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================