==================================================================
BUG: KASAN: use-after-free in skb_copy_bits+0x6f0/0x780 net/core/skbuff.c:2364
Read of size 4 at addr ffff888078d80430 by task ksoftirqd/1/19

CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:256
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
 skb_copy_bits+0x6f0/0x780 net/core/skbuff.c:2364
 __skb_header_pointer include/linux/skbuff.h:3706 [inline]
 skb_header_pointer include/linux/skbuff.h:3715 [inline]
 do_basic_checks net/netfilter/nf_conntrack_proto_sctp.c:174 [inline]
 nf_conntrack_sctp_packet+0xe34/0x2500 net/netfilter/nf_conntrack_proto_sctp.c:383
 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1845 [inline]
 nf_conntrack_in+0xfe8/0x15e0 net/netfilter/nf_conntrack_core.c:1918
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:589
 nf_hook.constprop.0+0x3ac/0x650 include/linux/netfilter.h:262
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ipv6_rcv+0x9e/0x3c0 net/ipv6/ip6_input.c:297
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5436
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5550
 process_backlog+0x2a5/0x6c0 net/core/dev.c:6427
 __napi_poll+0xaf/0x440 net/core/dev.c:6986
 napi_poll net/core/dev.c:7053 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:7140
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 run_ksoftirqd kernel/softirq.c:920 [inline]
 run_ksoftirqd+0x2d/0x60 kernel/softirq.c:912
 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Allocated by task 19:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x83/0xb0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:3206 [inline]
 kmem_cache_alloc_node+0x259/0x3d0 mm/slub.c:3242
 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414
 alloc_skb include/linux/skbuff.h:1116 [inline]
 sctp_packet_pack net/sctp/output.c:471 [inline]
 sctp_packet_transmit+0xc6d/0x3000 net/sctp/output.c:617
 sctp_outq_flush_transports+0x406/0x7b0 net/sctp/outqueue.c:1163
 sctp_outq_flush net/sctp/outqueue.c:1211 [inline]
 sctp_outq_uncork+0x185/0x200 net/sctp/outqueue.c:758
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1812 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1195 [inline]
 sctp_do_sm+0x745/0x4ed0 net/sctp/sm_sideeffect.c:1166
 sctp_assoc_bh_rcv+0x386/0x6c0 net/sctp/associola.c:1054
 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:80
 sctp_rcv+0xfe3/0x32a0 net/sctp/input.c:256
 sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109
 ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422
 ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472
 dst_input include/net/dst.h:460 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5436
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5550
 process_backlog+0x2a5/0x6c0 net/core/dev.c:6427
 __napi_poll+0xaf/0x440 net/core/dev.c:6986
 napi_poll net/core/dev.c:7053 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:7140
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558

Freed by task 19:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1700 [inline]
 slab_free_freelist_hook+0x81/0x190 mm/slub.c:1725
 slab_free mm/slub.c:3483 [inline]
 kmem_cache_free+0x8a/0x5b0 mm/slub.c:3499
 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:699
 __kfree_skb net/core/skbuff.c:756 [inline]
 consume_skb net/core/skbuff.c:911 [inline]
 consume_skb+0xcf/0x160 net/core/skbuff.c:905
 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1503 [inline]
 sctp_chunk_put+0x1c0/0x2d0 net/sctp/sm_make_chunk.c:1530
 sctp_inq_free+0x17f/0x260 net/sctp/inqueue.c:56
 sctp_association_free+0x229/0x7d0 net/sctp/associola.c:348
 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:940 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1324 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1195 [inline]
 sctp_do_sm+0x3665/0x4ed0 net/sctp/sm_sideeffect.c:1166
 sctp_assoc_bh_rcv+0x386/0x6c0 net/sctp/associola.c:1054
 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:80
 sctp_rcv+0xfe3/0x32a0 net/sctp/input.c:256
 sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109
 ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422
 ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472
 dst_input include/net/dst.h:460 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5436
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5550
 process_backlog+0x2a5/0x6c0 net/core/dev.c:6427
 __napi_poll+0xaf/0x440 net/core/dev.c:6986
 napi_poll net/core/dev.c:7053 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:7140
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558

The buggy address belongs to the object at ffff888078d803c0
 which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 112 bytes inside of
 232-byte region [ffff888078d803c0, ffff888078d804a8)
The buggy address belongs to the page:
page:ffffea0001e36000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78d80
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888015f81140
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 19, ts 2036822559534, free_ts 2036595910943
 prep_new_page mm/page_alloc.c:2424 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4153
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5375
 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2197
 alloc_slab_page mm/slub.c:1763 [inline]
 allocate_slab mm/slub.c:1900 [inline]
 new_slab+0x319/0x490 mm/slub.c:1963
 ___slab_alloc+0x921/0xfe0 mm/slub.c:2994
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3081
 slab_alloc_node mm/slub.c:3172 [inline]
 slab_alloc mm/slub.c:3214 [inline]
 kmem_cache_alloc+0x365/0x390 mm/slub.c:3219
 skb_clone+0x170/0x3c0 net/core/skbuff.c:1520
 dev_queue_xmit_nit+0x38c/0xa90 net/core/dev.c:2288
 xmit_one net/core/dev.c:3571 [inline]
 dev_hard_start_xmit+0xad/0x920 net/core/dev.c:3592
 sch_direct_xmit+0x19f/0xbc0 net/sched/sch_generic.c:342
 qdisc_restart net/sched/sch_generic.c:407 [inline]
 __qdisc_run+0x4bc/0x1700 net/sched/sch_generic.c:415
 __dev_xmit_skb net/core/dev.c:3861 [inline]
 __dev_queue_xmit+0x1f9c/0x36e0 net/core/dev.c:4170
 neigh_hh_output include/net/neighbour.h:499 [inline]
 neigh_output include/net/neighbour.h:508 [inline]
 ip6_finish_output2+0x922/0x1500 net/ipv6/ip6_output.c:126
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 __ip6_finish_output+0x4c1/0x1050 net/ipv6/ip6_output.c:170
 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1338 [inline]
 free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3315 [inline]
 free_unref_page_list+0x1a9/0xfa0 mm/page_alloc.c:3431
 release_pages+0x830/0x20b0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:242 [inline]
 tlb_flush_mmu mm/mmu_gather.c:249 [inline]
 tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:340
 exit_mmap+0x1ea/0x630 mm/mmap.c:3173
 __mmput+0x122/0x4b0 kernel/fork.c:1115
 mmput+0x58/0x60 kernel/fork.c:1136
 exit_mm kernel/exit.c:501 [inline]
 do_exit+0xabc/0x2a30 kernel/exit.c:812
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2160 kernel/signal.c:2868
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff888078d80300: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
 ffff888078d80380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff888078d80400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888078d80480: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
 ffff888078d80500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================