================================================================== 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 ffff88808d2942e0 by task syz-executor.2/32459 CPU: 1 PID: 32459 Comm: syz-executor.2 Not tainted 5.0.0-rc7+ #95 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:1904 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2080 __fib6_rule_action net/ipv6/fib6_rules.c:233 [inline] fib6_rule_action+0x3ac/0xab0 net/ipv6/fib6_rules.c:264 fib_rules_lookup+0x351/0xa90 net/core/fib_rules.c:304 fib6_rule_lookup+0x33c/0x560 net/ipv6/fib6_rules.c:110 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2109 ip6_route_output include/net/ip6_route.h:88 [inline] ip6_dst_lookup_tail+0xd10/0x1b30 net/ipv6/ip6_output.c:958 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1086 sctp_v6_get_dst+0x785/0x1d80 net/sctp/ipv6.c:293 sctp_transport_route+0x132/0x370 net/sctp/transport.c:312 sctp_assoc_add_peer+0x53e/0xfc0 net/sctp/associola.c:678 sctp_process_param net/sctp/sm_make_chunk.c:2548 [inline] sctp_process_init+0x2499/0x2b20 net/sctp/sm_make_chunk.c:2361 sctp_sf_do_5_1B_init+0x8ba/0xe50 net/sctp/sm_statefuns.c:416 sctp_do_sm+0x124/0x5380 net/sctp/sm_sideeffect.c:1188 sctp_endpoint_bh_rcv+0x451/0x950 net/sctp/endpointola.c:456 sctp_inq_push+0x1ea/0x290 net/sctp/inqueue.c:95 sctp_rcv+0x27d9/0x3550 net/sctp/input.c:271 sctp6_rcv+0x17/0x30 net/sctp/ipv6.c:1063 ip6_protocol_deliver_rcu+0x303/0x16c0 net/ipv6/ip6_input.c:394 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:443 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x1e7/0x320 net/ipv6/ip6_input.c:76 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 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:337 do_softirq kernel/softirq.c:329 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:189 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:696 [inline] ip6_finish_output2+0xbcf/0x2550 net/ipv6/ip6_output.c:121 ip6_finish_output+0x577/0xc30 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip6_xmit+0xe41/0x20c0 net/ipv6/ip6_output.c:275 sctp_v6_xmit+0x313/0x660 net/sctp/ipv6.c:232 sctp_packet_transmit+0x1b8b/0x3660 net/sctp/output.c:641 sctp_packet_singleton net/sctp/outqueue.c:787 [inline] sctp_outq_flush_ctrl.constprop.0+0x741/0xd40 net/sctp/outqueue.c:918 sctp_outq_flush+0xe8/0x2790 net/sctp/outqueue.c:1200 sctp_outq_uncork+0x6c/0x80 net/sctp/outqueue.c:772 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1820 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] sctp_do_sm+0x513/0x5380 net/sctp/sm_sideeffect.c:1191 sctp_primitive_ASSOCIATE+0x9d/0xd0 net/sctp/primitive.c:88 __sctp_connect+0x8cd/0xce0 net/sctp/socket.c:1226 __sctp_setsockopt_connectx+0x133/0x1a0 net/sctp/socket.c:1349 sctp_setsockopt_connectx_old net/sctp/socket.c:1365 [inline] sctp_setsockopt net/sctp/socket.c:4380 [inline] sctp_setsockopt+0x1bb2/0x5130 net/sctp/socket.c:4344 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2991 __sys_setsockopt+0x180/0x280 net/socket.c:1900 __do_sys_setsockopt net/socket.c:1911 [inline] __se_sys_setsockopt net/socket.c:1908 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1908 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7c05f2cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457e29 RDX: 000000000000006b RSI: 0000000000000084 RDI: 0000000000000005 RBP: 000000000073bfa0 R08: 000000000000001c R09: 0000000000000000 R10: 000000002055bfe4 R11: 0000000000000246 R12: 00007f7c05f2d6d4 R13: 00000000004cc9c8 R14: 00000000004da730 R15: 00000000ffffffff Allocated by task 7742: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:503 slab_post_alloc_hook mm/slab.h:440 [inline] slab_alloc mm/slab.c:3388 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3548 anon_vma_chain_alloc mm/rmap.c:129 [inline] anon_vma_clone+0xde/0x480 mm/rmap.c:269 anon_vma_fork+0x8f/0x4a0 mm/rmap.c:332 dup_mmap kernel/fork.c:541 [inline] dup_mm kernel/fork.c:1320 [inline] copy_mm kernel/fork.c:1375 [inline] copy_process.part.0+0x350f/0x79a0 kernel/fork.c:1917 copy_process kernel/fork.c:1710 [inline] _do_fork+0x257/0xfe0 kernel/fork.c:2227 __do_sys_clone kernel/fork.c:2334 [inline] __se_sys_clone kernel/fork.c:2328 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2328 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 23538: 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:457 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465 __cache_free mm/slab.c:3494 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3754 anon_vma_chain_free mm/rmap.c:134 [inline] unlink_anon_vmas+0x2ba/0x870 mm/rmap.c:401 free_pgtables+0x1af/0x2f0 mm/memory.c:393 exit_mmap+0x2d1/0x530 mm/mmap.c:3141 __mmput kernel/fork.c:1047 [inline] mmput+0x15f/0x4c0 kernel/fork.c:1068 exit_mm kernel/exit.c:545 [inline] do_exit+0x838/0x2fd0 kernel/exit.c:862 do_group_exit+0x135/0x370 kernel/exit.c:979 get_signal+0x399/0x1d50 kernel/signal.c:2575 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 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 ffff88808d2942a0 which belongs to the cache anon_vma_chain(33:syz1) of size 80 The buggy address is located 64 bytes inside of 80-byte region [ffff88808d2942a0, ffff88808d2942f0) The buggy address belongs to the page: page:ffffea000234a500 count:1 mapcount:0 mapping:ffff888087c559c0 index:0xffff88808d294460 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00027a4a48 ffffea0002604c88 ffff888087c559c0 raw: ffff88808d294460 ffff88808d294000 0000000100000012 ffff88806a2f4ec0 page dumped because: kasan: bad access detected page->mem_cgroup:ffff88806a2f4ec0 Memory state around the buggy address: ffff88808d294180: fb fb fb fb fc fc fc fc fb fb fb fb fb fb fb fb ffff88808d294200: fb fb fc fc fc fc fb fb fb fb fb fb fb fb fb fb >ffff88808d294280: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fc fc ^ ffff88808d294300: fc fc fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88808d294380: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fb fb ==================================================================