================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic-fallback.h:1086 [inline] BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic-fallback.h:1111 [inline] BUG: KASAN: use-after-free in atomic_inc_not_zero include/linux/atomic-fallback.h:1127 [inline] BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:297 [inline] BUG: KASAN: use-after-free in ip6_hold_safe+0xad/0x380 net/ipv6/route.c:1046 Read of size 4 at addr ffff888099a32824 by task kworker/0:0/5 CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.2.0-rc3+ #45 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events rt6_probe_deferred Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 kasan_check_read+0x11/0x20 mm/kasan/common.c:94 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] atomic_fetch_add_unless include/linux/atomic-fallback.h:1086 [inline] atomic_add_unless include/linux/atomic-fallback.h:1111 [inline] atomic_inc_not_zero include/linux/atomic-fallback.h:1127 [inline] dst_hold_safe include/net/dst.h:297 [inline] ip6_hold_safe+0xad/0x380 net/ipv6/route.c:1046 rt6_get_pcpu_route net/ipv6/route.c:1273 [inline] ip6_pol_route+0x339/0x1050 net/ipv6/route.c:1952 ip6_pol_route_input+0x65/0x80 net/ipv6/route.c:1971 fib6_rule_lookup+0x133/0x5a0 net/ipv6/fib6_rules.c:116 ip6_route_input_lookup+0xb7/0xd0 net/ipv6/route.c:1983 ip6_route_input+0x5e2/0x9e0 net/ipv6/route.c:2118 ip6_rcv_finish_core.isra.0+0x174/0x590 net/ipv6/ip6_input.c:63 ip6_rcv_finish+0x17a/0x310 net/ipv6/ip6_input.c:74 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:4981 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5095 process_backlog+0x206/0x750 net/core/dev.c:5906 napi_poll net/core/dev.c:6329 [inline] net_rx_action+0x4f5/0x1070 net/core/dev.c:6395 __do_softirq+0x25c/0x94c kernel/softirq.c:293 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1040 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:338 do_softirq kernel/softirq.c:330 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:190 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline] ip6_finish_output2+0x10a0/0x2550 net/ipv6/ip6_output.c:117 ip6_finish_output+0x56d/0xc20 net/ipv6/ip6_output.c:150 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:167 dst_output include/net/dst.h:433 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ndisc_send_skb+0xf29/0x14a0 net/ipv6/ndisc.c:504 ndisc_send_ns+0x3a9/0x850 net/ipv6/ndisc.c:646 rt6_probe_deferred+0xe3/0x1a0 net/ipv6/route.c:539 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 20061: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc_node mm/slab.c:3620 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3627 kmalloc_node include/linux/slab.h:590 [inline] kvmalloc_node+0x68/0x100 mm/util.c:431 kvmalloc include/linux/mm.h:637 [inline] seq_buf_alloc fs/seq_file.c:32 [inline] seq_read+0x817/0x1110 fs/seq_file.c:204 __vfs_read+0x8a/0x110 fs/read_write.c:425 vfs_read+0x194/0x3e0 fs/read_write.c:461 ksys_read+0x14f/0x290 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:595 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 20061: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:460 seq_release fs/seq_file.c:360 [inline] single_release+0x7e/0xc0 fs/seq_file.c:597 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:185 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888099a32540 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 740 bytes inside of 4096-byte region [ffff888099a32540, ffff888099a33540) The buggy address belongs to the page: page:ffffea0002668c80 refcount:1 mapcount:0 mapping:ffff8880aa400dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002448508 ffffea00018e0108 ffff8880aa400dc0 raw: 0000000000000000 ffff888099a32540 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888099a32700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888099a32780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888099a32800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888099a32880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888099a32900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================