================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline] BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [inline] BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline] BUG: KASAN: use-after-free in ip6_hold_safe+0xa7/0x3a0 net/ipv6/route.c:1023 Read of size 4 at addr ffff888088ca92a0 by task ksoftirqd/1/16 CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.0.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 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:100 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] atomic_fetch_add_unless include/linux/atomic.h:575 [inline] atomic_add_unless include/linux/atomic.h:597 [inline] dst_hold_safe include/net/dst.h:308 [inline] ip6_hold_safe+0xa7/0x3a0 net/ipv6/route.c:1023 rt6_get_pcpu_route net/ipv6/route.c:1243 [inline] ip6_pol_route+0x33d/0xf00 net/ipv6/route.c:1892 ip6_pol_route_input+0x65/0x80 net/ipv6/route.c:1911 fib6_rule_lookup+0x128/0x560 net/ipv6/fib6_rules.c:118 ip6_route_input_lookup+0xb7/0xd0 net/ipv6/route.c:1923 ip6_route_input+0x5e6/0x9e0 net/ipv6/route.c:2058 ip6_rcv_finish_core.isra.0+0x174/0x590 net/ipv6/ip6_input.c:63 ip6_rcv_finish+0x17d/0x320 net/ipv6/ip6_input.c:74 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x115/0x1a0 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083 process_backlog+0x206/0x750 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x4fa/0x1070 net/core/dev.c:6412 __do_softirq+0x266/0x95a kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:654 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646 smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Allocated by task 12644: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 __do_kmalloc_node mm/slab.c:3673 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3680 kmalloc_node include/linux/slab.h:588 [inline] kvmalloc_node+0x68/0x100 mm/util.c:416 kvmalloc include/linux/mm.h:604 [inline] seq_buf_alloc fs/seq_file.c:32 [inline] seq_read+0x832/0x1130 fs/seq_file.c:204 __vfs_read+0x116/0x8c0 fs/read_write.c:416 vfs_read+0x194/0x3e0 fs/read_write.c:452 ksys_read+0xea/0x1f0 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12644: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 kvfree+0x61/0x70 mm/util.c:445 seq_release fs/seq_file.c:359 [inline] single_release+0x7e/0xc0 fs/seq_file.c:596 __fput+0x2df/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888088ca8880 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2592 bytes inside of 4096-byte region [ffff888088ca8880, ffff888088ca9880) The buggy address belongs to the page: page:ffffea0002232a00 count:1 mapcount:0 mapping:ffff88812c3f0dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00024dbf08 ffffea0000d9e988 ffff88812c3f0dc0 raw: 0000000000000000 ffff888088ca8880 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888088ca9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb netlink: 'syz-executor.2': attribute type 10 has an invalid length. ffff888088ca9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888088ca9280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888088ca9300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888088ca9380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================