================================================================== 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:1050 Read of size 4 at addr ffff888095173440 by task syz-executor.2/17646 CPU: 0 PID: 17646 Comm: syz-executor.2 Not tainted 5.1.0+ #7 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: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:1050 rt6_get_pcpu_route net/ipv6/route.c:1277 [inline] ip6_pol_route+0x339/0xfa0 net/ipv6/route.c:1936 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2112 fib6_rule_lookup+0x136/0x5a0 net/ipv6/fib6_rules.c:116 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2141 ip6_route_output include/net/ip6_route.h:89 [inline] ip6_dst_lookup_tail+0xd10/0x1b30 net/ipv6/ip6_output.c:966 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1094 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:2546 [inline] sctp_process_init+0x249f/0x2b20 net/sctp/sm_make_chunk.c:2359 sctp_sf_do_unexpected_init net/sctp/sm_statefuns.c:1556 [inline] sctp_sf_do_unexpected_init.isra.0+0x7cd/0x1350 net/sctp/sm_statefuns.c:1456 sctp_sf_do_5_2_1_siminit+0x35/0x40 net/sctp/sm_statefuns.c:1685 sctp_do_sm+0x12c/0x5500 net/sctp/sm_sideeffect.c:1162 sctp_assoc_bh_rcv+0x343/0x660 net/sctp/associola.c:1074 sctp_inq_push+0x1ea/0x290 net/sctp/inqueue.c:95 sctp_backlog_rcv+0x196/0xbe0 net/sctp/input.c:354 sk_backlog_rcv include/net/sock.h:950 [inline] __release_sock+0x12e/0x3a0 net/core/sock.c:2418 release_sock+0x59/0x1c0 net/core/sock.c:2934 sctp_wait_for_connect+0x316/0x540 net/sctp/socket.c:9054 __sctp_connect+0xac2/0xce0 net/sctp/socket.c:1241 sctp_connect net/sctp/socket.c:4861 [inline] sctp_inet_connect+0x2a2/0x340 net/sctp/socket.c:4877 __sys_connect+0x266/0x330 net/socket.c:1840 __do_sys_connect net/socket.c:1851 [inline] __se_sys_connect net/socket.c:1848 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1848 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 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:00007f6ad6a95c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9 RDX: 000000000000001c RSI: 0000000020000200 RDI: 0000000000000003 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6ad6a966d4 R13: 00000000004bf1fe R14: 00000000004d04b8 R15: 00000000ffffffff Allocated by task 16868: 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_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:437 [inline] slab_alloc mm/slab.c:3357 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3519 dst_alloc+0x10e/0x200 net/core/dst.c:92 ip6_dst_alloc+0x34/0xa0 net/ipv6/route.c:356 icmp6_dst_alloc+0x1a9/0x660 net/ipv6/route.c:2718 ndisc_send_skb+0xfc6/0x14a0 net/ipv6/ndisc.c:488 ndisc_send_ns+0x3a9/0x860 net/ipv6/ndisc.c:650 rt6_probe_deferred+0xe3/0x1a0 net/ipv6/route.c:543 process_one_work+0x98e/0x1790 kernel/workqueue.c:2268 worker_thread+0x98/0xe40 kernel/workqueue.c:2414 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Freed by task 26516: 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:3463 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3729 dst_destroy+0x2a0/0x3c0 net/core/dst.c:128 dst_destroy_rcu+0x16/0x19 net/core/dst.c:141 __rcu_reclaim kernel/rcu/rcu.h:227 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0x973/0x1430 kernel/rcu/tree.c:2291 __do_softirq+0x266/0x95a kernel/softirq.c:293 The buggy address belongs to the object at ffff888095173440 which belongs to the cache ip6_dst_cache of size 224 The buggy address is located 0 bytes inside of 224-byte region [ffff888095173440, ffff888095173520) The buggy address belongs to the page: page:ffffea0002545cc0 count:1 mapcount:0 mapping:ffff88809b6ed9c0 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0001afd948 ffffea0002512f88 ffff88809b6ed9c0 raw: 0000000000000000 ffff888095173080 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095173300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888095173380: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff888095173400: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff888095173480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888095173500: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================