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BUG: KASAN: slab-out-of-bounds in instrument_atomic_read include/linux/instrumented.h:82 [inline]
BUG: KASAN: slab-out-of-bounds in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-out-of-bounds in inet_sk_flowi_flags include/net/inet_sock.h:411 [inline]
BUG: KASAN: slab-out-of-bounds in tcp_v6_send_response+0x116c/0x1e30 net/ipv6/tcp_ipv6.c:983
Read of size 8 at addr ffff8881bc3cecb8 by task kworker/u8:3/5678

CPU: 1 UID: 0 PID: 5678 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: krdsd rds_tcp_accept_worker
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read include/linux/instrumented.h:82 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 inet_sk_flowi_flags include/net/inet_sock.h:411 [inline]
 tcp_v6_send_response+0x116c/0x1e30 net/ipv6/tcp_ipv6.c:983
 tcp_v6_send_ack net/ipv6/tcp_ipv6.c:1149 [inline]
 tcp_v6_timewait_ack+0x2c6/0x4c0 net/ipv6/tcp_ipv6.c:1201
 tcp_v6_rcv+0x1f09/0x2d90 net/ipv6/tcp_ipv6.c:1993
 ip6_protocol_deliver_rcu+0xab9/0x1680 net/ipv6/ip6_input.c:479
 ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:534
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
 __netif_receive_skb_one_core net/core/dev.c:6264 [inline]
 __netif_receive_skb net/core/dev.c:6377 [inline]
 process_backlog+0x795/0x18b0 net/core/dev.c:6728
 __napi_poll+0xaa/0x330 net/core/dev.c:7787
 napi_poll net/core/dev.c:7850 [inline]
 net_rx_action+0x61d/0xf50 net/core/dev.c:8007
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 do_softirq+0x77/0xd0 kernel/softirq.c:546
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:923 [inline]
 __dev_queue_xmit+0x1edc/0x3820 net/core/dev.c:4961
 NF_HOOK_COND include/linux/netfilter.h:314 [inline]
 ip6_output+0x337/0x540 net/ipv6/ip6_output.c:248
 dst_output include/net/dst.h:471 [inline]
 NF_HOOK include/linux/netfilter.h:325 [inline]
 ip6_xmit+0x117f/0x1a60 net/ipv6/ip6_output.c:381
 inet6_csk_xmit+0x397/0x660 net/ipv6/inet6_connection_sock.c:123
 __tcp_transmit_skb+0x2640/0x47c0 net/ipv4/tcp_output.c:1717
 tcp_transmit_skb net/ipv4/tcp_output.c:1734 [inline]
 tcp_write_xmit+0x1bfa/0x6400 net/ipv4/tcp_output.c:3062
 __tcp_push_pending_frames+0x96/0x380 net/ipv4/tcp_output.c:3245
 __tcp_close+0x56e/0xe70 net/ipv4/tcp.c:3220
 tcp_close+0x28/0x110 net/ipv4/tcp.c:3311
 inet_release+0x143/0x190 net/ipv4/af_inet.c:442
 __sock_release net/socket.c:735 [inline]
 sock_release+0x85/0x150 net/socket.c:763
 rds_tcp_accept_one+0x62c/0xd40 net/rds/tcp_listen.c:341
 rds_tcp_accept_worker+0x1d/0x70 net/rds/tcp.c:556
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the object at ffff8881bc3ceb80
 which belongs to the cache tw_sock_TCPv6 of size 304
The buggy address is located 8 bytes to the right of
 allocated 304-byte region [ffff8881bc3ceb80, ffff8881bc3cecb0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881bc3ce8a0 pfn:0x1bc3ce
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8881bb1a4301
flags: 0x57ff00000000240(workingset|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000240 ffff8881042e0640 ffff88816fedf1c8 ffff88816fedf1c8
raw: ffff8881bc3ce8a0 0000000200160006 00000000f5000000 ffff8881bb1a4301
head: 057ff00000000240 ffff8881042e0640 ffff88816fedf1c8 ffff88816fedf1c8
head: ffff8881bc3ce8a0 0000000200160006 00000000f5000000 ffff8881bb1a4301
head: 057ff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5678, tgid 5678 (kworker/u8:3), ts 57920184007
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7410
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 kmem_cache_alloc_noprof+0x399/0x600 mm/slub.c:5010
 inet_twsk_alloc+0xe3/0x8d0 net/ipv4/inet_timewait_sock.c:178
 tcp_time_wait+0x5d/0xee0 net/ipv4/tcp_minisocks.c:333
 tcp_rcv_state_process+0xba1/0x4980 net/ipv4/tcp_input.c:-1
 tcp_v6_do_rcv+0xf3d/0x1c70 net/ipv6/tcp_ipv6.c:1653
 tcp_v6_rcv+0x2496/0x2d90 net/ipv6/tcp_ipv6.c:1906
 ip6_protocol_deliver_rcu+0xab9/0x1680 net/ipv6/ip6_input.c:479
 ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:534
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
page last free pid 24 tgid 24 ts 57909757259 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
 rcu_do_batch kernel/rcu/tree.c:2650 [inline]
 rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:267 [inline]
 sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:267
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:681

Memory state around the buggy address:
 ffff8881bc3ceb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881bc3cec00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881bc3cec80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                        ^
 ffff8881bc3ced00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881bc3ced80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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