FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 1
CPU: 0 UID: 0 PID: 5114 Comm: syz.0.0 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x3b0/0x4e0 lib/fault-inject.c:153
 should_failslab+0xac/0x100 mm/failslab.c:45
 slab_pre_alloc_hook mm/slub.c:3941 [inline]
 slab_alloc_node mm/slub.c:4017 [inline]
 __kmalloc_cache_noprof+0x6c/0x2c0 mm/slub.c:4184
 kmalloc_noprof include/linux/slab.h:681 [inline]
 dccp_feat_entry_new+0x173/0x3a0 net/dccp/feat.c:464
 dccp_feat_push_confirm net/dccp/feat.c:512 [inline]
 dccp_feat_handle_nn_established net/dccp/feat.c:1349 [inline]
 dccp_feat_parse_options+0xeac/0x2c30 net/dccp/feat.c:1435
 dccp_parse_options+0x13bd/0x2670 net/dccp/options.c:125
 dccp_rcv_established+0x55/0x320 net/dccp/input.c:370
 dccp_v6_do_rcv+0x28e/0xb10 net/dccp/ipv6.c:625
 sk_backlog_rcv include/net/sock.h:1111 [inline]
 __release_sock+0x243/0x350 net/core/sock.c:3004
 release_sock+0x61/0x1f0 net/core/sock.c:3558
 dccp_sendmsg+0x4f0/0xba0 net/dccp/proto.c:803
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
 __do_sys_sendmmsg net/socket.c:2766 [inline]
 __se_sys_sendmmsg net/socket.c:2763 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b2f979eb9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b30719038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f2b2fb15f80 RCX: 00007f2b2f979eb9
RDX: 0000000000000003 RSI: 000000002001a800 RDI: 0000000000000005
RBP: 00007f2b30719090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000010 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007f2b2fb15f80 R15: 00007ffd0956e208
 </TASK>
dccp_parse_options: DCCP(ffff88803c402b00): Option 32 (len=7) error=9
==================================================================
BUG: KASAN: slab-use-after-free in dccp_ackvec_runlen net/dccp/ackvec.h:43 [inline]
BUG: KASAN: slab-use-after-free in ccid2_hc_tx_packet_recv+0x1902/0x2070 net/dccp/ccids/ccid2.c:593
Read of size 1 at addr ffff88804a4734a2 by task syz.0.0/5114

CPU: 0 UID: 0 PID: 5114 Comm: syz.0.0 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 dccp_ackvec_runlen net/dccp/ackvec.h:43 [inline]
 ccid2_hc_tx_packet_recv+0x1902/0x2070 net/dccp/ccids/ccid2.c:593
 ccid_hc_tx_packet_recv net/dccp/ccid.h:189 [inline]
 dccp_deliver_input_to_ccids net/dccp/input.c:182 [inline]
 dccp_rcv_established+0x295/0x320 net/dccp/input.c:374
 dccp_v6_do_rcv+0x28e/0xb10 net/dccp/ipv6.c:625
 sk_backlog_rcv include/net/sock.h:1111 [inline]
 __release_sock+0x243/0x350 net/core/sock.c:3004
 release_sock+0x61/0x1f0 net/core/sock.c:3558
 dccp_sendmsg+0x4f0/0xba0 net/dccp/proto.c:803
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
 __do_sys_sendmmsg net/socket.c:2766 [inline]
 __se_sys_sendmmsg net/socket.c:2763 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b2f979eb9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b30719038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f2b2fb15f80 RCX: 00007f2b2f979eb9
RDX: 0000000000000003 RSI: 000000002001a800 RDI: 0000000000000005
RBP: 00007f2b30719090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000010 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007f2b2fb15f80 R15: 00007ffd0956e208
 </TASK>

Allocated by task 5114:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slub.c:4158 [inline]
 __kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4177
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:605
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1320 [inline]
 dccp_send_ack+0xaa/0x310 net/dccp/output.c:585
 ccid2_hc_rx_packet_recv+0x10c/0x1c0 net/dccp/ccids/ccid2.c:772
 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline]
 dccp_deliver_input_to_ccids net/dccp/input.c:176 [inline]
 dccp_rcv_established+0x1bb/0x320 net/dccp/input.c:374
 dccp_v6_do_rcv+0x28e/0xb10 net/dccp/ipv6.c:625
 sk_backlog_rcv include/net/sock.h:1111 [inline]
 __sk_receive_skb+0x82b/0x8b0 net/core/sock.c:569
 dccp_v6_rcv+0x1189/0x1640 net/dccp/ipv6.c:794
 ip6_protocol_deliver_rcu+0x105b/0x1580 net/ipv6/ip6_input.c:438
 ip6_input_finish+0x187/0x2d0 net/ipv6/ip6_input.c:483
 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
 __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
 __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5775
 process_backlog+0x662/0x15b0 net/core/dev.c:6108
 __napi_poll+0xcb/0x490 net/core/dev.c:6772
 napi_poll net/core/dev.c:6841 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:6963
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
 __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
 dev_queue_xmit include/linux/netdevice.h:3105 [inline]
 neigh_hh_output include/net/neighbour.h:526 [inline]
 neigh_output include/net/neighbour.h:540 [inline]
 ip6_finish_output2+0xfc9/0x1730 net/ipv6/ip6_output.c:141
 ip6_finish_output+0x41e/0x810 net/ipv6/ip6_output.c:226
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip6_xmit+0xef8/0x18b0 net/ipv6/ip6_output.c:366
 inet6_csk_xmit+0x468/0x710 net/ipv6/inet6_connection_sock.c:135
 dccp_transmit_skb+0xf41/0x16a0 net/dccp/output.c:138
 dccp_xmit_packet+0x376/0x610 net/dccp/output.c:281
 dccp_write_xmit+0x138/0x220 net/dccp/output.c:366
 dccp_sendmsg+0x76f/0xba0 net/dccp/proto.c:801
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
 __do_sys_sendmmsg net/socket.c:2766 [inline]
 __se_sys_sendmmsg net/socket.c:2763 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5114:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x149/0x360 mm/slub.c:4594
 skb_kfree_head net/core/skbuff.c:1084 [inline]
 skb_free_head net/core/skbuff.c:1096 [inline]
 skb_release_data+0x676/0x880 net/core/skbuff.c:1123
 skb_release_all net/core/skbuff.c:1188 [inline]
 __kfree_skb net/core/skbuff.c:1202 [inline]
 sk_skb_reason_drop+0x1a5/0x3d0 net/core/skbuff.c:1240
 dccp_v6_do_rcv+0x133/0xb10
 sk_backlog_rcv include/net/sock.h:1111 [inline]
 __release_sock+0x243/0x350 net/core/sock.c:3004
 release_sock+0x61/0x1f0 net/core/sock.c:3558
 dccp_sendmsg+0x4f0/0xba0 net/dccp/proto.c:803
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
 __do_sys_sendmmsg net/socket.c:2766 [inline]
 __se_sys_sendmmsg net/socket.c:2763 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88804a473000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1186 bytes inside of
 freed 2048-byte region [ffff88804a473000, ffff88804a473800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4a470
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 04fff00000000040 ffff88801ac42000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000080008 00000001fdffffff 0000000000000000
head: 04fff00000000040 ffff88801ac42000 dead000000000122 0000000000000000
head: 0000000000000000 0000000000080008 00000001fdffffff 0000000000000000
head: 04fff00000000003 ffffea0001291c01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5114, tgid 5113 (syz.0.0), ts 79439101340, free_ts 79211244345
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2321
 allocate_slab+0x5a/0x2f0 mm/slub.c:2484
 new_slab mm/slub.c:2537 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
 __slab_alloc+0x58/0xa0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 __do_kmalloc_node mm/slub.c:4157 [inline]
 __kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4177
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:605
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1320 [inline]
 alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6526
 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815
 sock_alloc_send_skb include/net/sock.h:1778 [inline]
 dccp_sendmsg+0x3f1/0xba0 net/dccp/proto.c:764
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
page last free pid 9 tgid 9 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612
 discard_slab mm/slub.c:2583 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3051
 put_cpu_partial+0x17c/0x250 mm/slub.c:3126
 __slab_free+0x2ea/0x3d0 mm/slub.c:4343
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4080
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:664
 alloc_skb include/linux/skbuff.h:1320 [inline]
 alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6526
 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815
 sock_alloc_send_skb include/net/sock.h:1778 [inline]
 mld_newpack+0x1c3/0xa90 net/ipv6/mcast.c:1746
 add_grhead net/ipv6/mcast.c:1849 [inline]
 add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1987
 mld_send_initial_cr+0x228/0x4b0 net/ipv6/mcast.c:2233
 mld_dad_work+0x44/0x500 net/ipv6/mcast.c:2259
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312

Memory state around the buggy address:
 ffff88804a473380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804a473400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804a473480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88804a473500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804a473580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================