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BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
BUG: KASAN: null-ptr-deref in atomic_fetch_add_unless include/linux/atomic-fallback.h:1086 [inline]
BUG: KASAN: null-ptr-deref in atomic_add_unless include/linux/atomic-fallback.h:1111 [inline]
BUG: KASAN: null-ptr-deref in atomic_inc_not_zero include/linux/atomic-fallback.h:1127 [inline]
BUG: KASAN: null-ptr-deref in dst_hold_safe include/net/dst.h:308 [inline]
BUG: KASAN: null-ptr-deref in ip6_hold_safe+0xb3/0x3a0 net/ipv6/route.c:1023
Read of size 4 at addr 000000000000007a by task syz-executor.1/32269

CPU: 0 PID: 32269 Comm: syz-executor.1 Not tainted 5.1.0-rc4+ #168
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
 kasan_report.cold+0x5/0x40 mm/kasan/report.c:321
 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:102
 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:308 [inline]
 ip6_hold_safe+0xb3/0x3a0 net/ipv6/route.c:1023
 rt6_get_pcpu_route net/ipv6/route.c:1245 [inline]
 ip6_pol_route+0x348/0x1040 net/ipv6/route.c:1906
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2082
 fib6_rule_lookup+0x128/0x560 net/ipv6/fib6_rules.c:118
 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2111
 ip6_route_output include/net/ip6_route.h:88 [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:2548 [inline]
 sctp_process_init+0x249f/0x2b20 net/sctp/sm_make_chunk.c:2361
 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/0x5770 net/sctp/sm_sideeffect.c:1188
 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:943 [inline]
 __release_sock+0x12e/0x3a0 net/core/sock.c:2413
 release_sock+0x59/0x1c0 net/core/sock.c:2929
 sctp_wait_for_connect+0x316/0x540 net/sctp/socket.c:9048
 __sctp_connect+0xac2/0xce0 net/sctp/socket.c:1241
 sctp_connect net/sctp/socket.c:4858 [inline]
 sctp_inet_connect+0x2a2/0x340 net/sctp/socket.c:4874
 __sys_connect+0x266/0x330 net/socket.c:1808
 __do_sys_connect net/socket.c:1819 [inline]
 __se_sys_connect net/socket.c:1816 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1816
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c29
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:00007fcc34402c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29
RDX: 000000000000001c RSI: 0000000020000080 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcc344036d4
R13: 00000000004bf05e R14: 00000000004d0140 R15: 00000000ffffffff
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