Re: Re: [moderation/CI] Re: netlink: fix skb refcount leak when dump start fails

[syzbot <syzbot@syzkaller.appspotmail.com>]

>>>>>>>>>>>>> #syz upstream
>>>>>>>>>>>>
>>>>>>>>>>>> Failed to process the command. Contact syzkaller@googlegroups.com.
>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Thu, May 28, 2026 at 4:39 PM syzbot ci
>>>>>>>>>>>>> <syzbot+cidbb9f477452b5813@syzkaller.appspotmail.com> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> syzbot ci has tested the following series
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> [v1] netlink: fix skb refcount leak when dump start fails
>>>>>>>>>>>>>> https://lore.kernel.org/all/20260528073614.1169858-1-vulab@iscas.ac.cn
>>>>>>>>>>>>>> * [PATCH] netlink: fix skb refcount leak when dump start fails
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> and found the following issues:
>>>>>>>>>>>>>> * KASAN: slab-use-after-free Read in nl80211_prepare_wdev_dump
>>>>>>>>>>>>>> * KASAN: slab-use-after-free Read in xfrm_dump_sa_done
>>>>>>>>>>>>>> * KASAN: slab-use-after-free Write in sk_skb_reason_drop
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Full report is available here:
>>>>>>>>>>>>>> https://ci.syzbot.org/series/8ed6f41d-0d02-4f1f-a7be-cc639c2b4cfd
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ***
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> KASAN: slab-use-after-free Read in nl80211_prepare_wdev_dump
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> tree:      net
>>>>>>>>>>>>>> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git
>>>>>>>>>>>>>> base:      18014147d3ee7831dce53fe65d7fc8d428b02552
>>>>>>>>>>>>>> arch:      amd64
>>>>>>>>>>>>>> compiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
>>>>>>>>>>>>>> config:    https://ci.syzbot.org/builds/90c5185d-0dad-4c34-a563-4253ebb12eb2/config
>>>>>>>>>>>>>> syz repro: https://ci.syzbot.org/findings/0ad9835c-f631-4240-a3ad-2610bca3de33/syz_repro
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ==================================================================
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in __nlmsg_parse include/net/netlink.h:784 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in nlmsg_parse_deprecated include/net/netlink.h:830 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in nl80211_prepare_wdev_dump+0x634/0x680 net/wireless/nl80211.c:1245
>>>>>>>>>>>>>> Read of size 4 at addr ffff88816e172d80 by task syz.0.17/5814
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> CPU: 1 UID: 0 PID: 5814 Comm: syz.0.17 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
>>>>>>>>>>>>>> Call Trace:
>>>>>>>>>>>>>>  <TASK>
>>>>>>>>>>>>>>  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
>>>>>>>>>>>>>>  __nlmsg_parse include/net/netlink.h:784 [inline]
>>>>>>>>>>>>>>  nlmsg_parse_deprecated include/net/netlink.h:830 [inline]
>>>>>>>>>>>>>>  nl80211_prepare_wdev_dump+0x634/0x680 net/wireless/nl80211.c:1245
>>>>>>>>>>>>>>  nl80211_dump_station+0x186/0xdb0 net/wireless/nl80211.c:8216
>>>>>>>>>>>>>>  genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
>>>>>>>>>>>>>>  netlink_dump+0x702/0xe10 net/netlink/af_netlink.c:2325
>>>>>>>>>>>>>>  netlink_recvmsg+0x690/0xa50 net/netlink/af_netlink.c:1976
>>>>>>>>>>>>>>  sock_recvmsg_nosec net/socket.c:1137 [inline]
>>>>>>>>>>>>>>  sock_recvmsg+0x172/0x1b0 net/socket.c:1159
>>>>>>>>>>>>>>  __sys_recvfrom+0x240/0x3c0 net/socket.c:2315
>>>>>>>>>>>>>>  __do_sys_recvfrom net/socket.c:2330 [inline]
>>>>>>>>>>>>>>  __se_sys_recvfrom net/socket.c:2326 [inline]
>>>>>>>>>>>>>>  __x64_sys_recvfrom+0xde/0x100 net/socket.c:2326
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>> RIP: 0033:0x7fd64155d68e
>>>>>>>>>>>>>> Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
>>>>>>>>>>>>>> RSP: 002b:00007fd6424b5e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
>>>>>>>>>>>>>> RAX: ffffffffffffffda RBX: 00007fd6424b76c0 RCX: 00007fd64155d68e
>>>>>>>>>>>>>> RDX: 0000000000001000 RSI: 00007fd6424b6000 RDI: 0000000000000003
>>>>>>>>>>>>>> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
>>>>>>>>>>>>>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
>>>>>>>>>>>>>> R13: 00007fd6424b5f58 R14: 00007fd6424b6000 R15: 0000000000000000
>>>>>>>>>>>>>>  </TASK>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Allocated by task 5813:
>>>>>>>>>>>>>>  kasan_save_stack mm/kasan/common.c:57 [inline]
>>>>>>>>>>>>>>  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
>>>>>>>>>>>>>>  unpoison_slab_object mm/kasan/common.c:340 [inline]
>>>>>>>>>>>>>>  __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
>>>>>>>>>>>>>>  kasan_slab_alloc include/linux/kasan.h:253 [inline]
>>>>>>>>>>>>>>  slab_post_alloc_hook mm/slub.c:4569 [inline]
>>>>>>>>>>>>>>  slab_alloc_node mm/slub.c:4898 [inline]
>>>>>>>>>>>>>>  kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4950
>>>>>>>>>>>>>>  kmalloc_reserve net/core/skbuff.c:613 [inline]
>>>>>>>>>>>>>>  __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
>>>>>>>>>>>>>>  netlink_sendmsg+0x5d4/0xb40 net/netlink/af_netlink.c:1869
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
>>>>>>>>>>>>>>  ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
>>>>>>>>>>>>>>  __sys_sendmsg net/socket.c:2784 [inline]
>>>>>>>>>>>>>>  __do_sys_sendmsg net/socket.c:2789 [inline]
>>>>>>>>>>>>>>  __se_sys_sendmsg net/socket.c:2787 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Freed by task 5813:
>>>>>>>>>>>>>>  kasan_save_stack mm/kasan/common.c:57 [inline]
>>>>>>>>>>>>>>  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
>>>>>>>>>>>>>>  kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
>>>>>>>>>>>>>>  poison_slab_object mm/kasan/common.c:253 [inline]
>>>>>>>>>>>>>>  __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
>>>>>>>>>>>>>>  kasan_slab_free include/linux/kasan.h:235 [inline]
>>>>>>>>>>>>>>  slab_free_hook mm/slub.c:2689 [inline]
>>>>>>>>>>>>>>  slab_free mm/slub.c:6250 [inline]
>>>>>>>>>>>>>>  kfree+0x1c5/0x640 mm/slub.c:6565
>>>>>>>>>>>>>>  skb_kfree_head net/core/skbuff.c:1075 [inline]
>>>>>>>>>>>>>>  skb_free_head net/core/skbuff.c:1087 [inline]
>>>>>>>>>>>>>>  skb_release_data+0x828/0xa60 net/core/skbuff.c:1114
>>>>>>>>>>>>>>  skb_release_all net/core/skbuff.c:1189 [inline]
>>>>>>>>>>>>>>  __kfree_skb+0x5d/0x210 net/core/skbuff.c:1203
>>>>>>>>>>>>>>  netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
>>>>>>>>>>>>>>  netlink_unicast+0x764/0x8e0 net/netlink/af_netlink.c:1344
>>>>>>>>>>>>>>  netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
>>>>>>>>>>>>>>  ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
>>>>>>>>>>>>>>  __sys_sendmsg net/socket.c:2784 [inline]
>>>>>>>>>>>>>>  __do_sys_sendmsg net/socket.c:2789 [inline]
>>>>>>>>>>>>>>  __se_sys_sendmsg net/socket.c:2787 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The buggy address belongs to the object at ffff88816e172d80
>>>>>>>>>>>>>>  which belongs to the cache skbuff_small_head of size 704
>>>>>>>>>>>>>> The buggy address is located 0 bytes inside of
>>>>>>>>>>>>>>  freed 704-byte region [ffff88816e172d80, ffff88816e173040)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The buggy address belongs to the physical page:
>>>>>>>>>>>>>> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16e170
>>>>>>>>>>>>>> head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
>>>>>>>>>>>>>> flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
>>>>>>>>>>>>>> page_type: f5(slab)
>>>>>>>>>>>>>> raw: 057ff00000000040 ffff888160415140 dead000000000100 dead000000000122
>>>>>>>>>>>>>> raw: 0000000000000000 0000000800120012 00000000f5000000 0000000000000000
>>>>>>>>>>>>>> head: 057ff00000000040 ffff888160415140 dead000000000100 dead000000000122
>>>>>>>>>>>>>> head: 0000000000000000 0000000800120012 00000000f5000000 0000000000000000
>>>>>>>>>>>>>> head: 057ff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
>>>>>>>>>>>>>> head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
>>>>>>>>>>>>>> page dumped because: kasan: bad access detected
>>>>>>>>>>>>>> page_owner tracks the page as allocated
>>>>>>>>>>>>>> page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5530, tgid 5530 (sshd), ts 47735478218, free_ts 34702748767
>>>>>>>>>>>>>>  set_page_owner include/linux/page_owner.h:32 [inline]
>>>>>>>>>>>>>>  post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1858
>>>>>>>>>>>>>>  prep_new_page mm/page_alloc.c:1866 [inline]
>>>>>>>>>>>>>>  get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
>>>>>>>>>>>>>>  __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
>>>>>>>>>>>>>>  alloc_slab_page mm/slub.c:3278 [inline]
>>>>>>>>>>>>>>  allocate_slab+0x77/0x660 mm/slub.c:3467
>>>>>>>>>>>>>>  new_slab mm/slub.c:3525 [inline]
>>>>>>>>>>>>>>  refill_objects+0x339/0x3d0 mm/slub.c:7271
>>>>>>>>>>>>>>  refill_sheaf mm/slub.c:2816 [inline]
>>>>>>>>>>>>>>  __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
>>>>>>>>>>>>>>  alloc_from_pcs mm/slub.c:4749 [inline]
>>>>>>>>>>>>>>  slab_alloc_node mm/slub.c:4883 [inline]
>>>>>>>>>>>>>>  kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4950
>>>>>>>>>>>>>>  kmalloc_reserve net/core/skbuff.c:613 [inline]
>>>>>>>>>>>>>>  __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
>>>>>>>>>>>>>>  alloc_skb include/linux/skbuff.h:1383 [inline]
>>>>>>>>>>>>>>  __tcp_send_ack+0xae/0x4f0 net/ipv4/tcp_output.c:4473
>>>>>>>>>>>>>>  tcp_cleanup_rbuf net/ipv4/tcp.c:1612 [inline]
>>>>>>>>>>>>>>  tcp_recvmsg_locked+0x2dfa/0x3720 net/ipv4/tcp.c:2916
>>>>>>>>>>>>>>  tcp_recvmsg+0x205/0x7e0 net/ipv4/tcp.c:2945
>>>>>>>>>>>>>>  sock_recvmsg_nosec net/socket.c:1137 [inline]
>>>>>>>>>>>>>>  sock_recvmsg+0x155/0x1b0 net/socket.c:1159
>>>>>>>>>>>>>>  sock_read_iter+0x251/0x320 net/socket.c:1229
>>>>>>>>>>>>>>  new_sync_read fs/read_write.c:493 [inline]
>>>>>>>>>>>>>>  vfs_read+0x582/0xa70 fs/read_write.c:574
>>>>>>>>>>>>>>  ksys_read+0x150/0x270 fs/read_write.c:717
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>> page last free pid 5059 tgid 5059 stack trace:
>>>>>>>>>>>>>>  reset_page_owner include/linux/page_owner.h:25 [inline]
>>>>>>>>>>>>>>  __free_pages_prepare mm/page_alloc.c:1402 [inline]
>>>>>>>>>>>>>>  __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
>>>>>>>>>>>>>>  __slab_free+0x274/0x2c0 mm/slub.c:5612
>>>>>>>>>>>>>>  qlink_free mm/kasan/quarantine.c:163 [inline]
>>>>>>>>>>>>>>  qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
>>>>>>>>>>>>>>  kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
>>>>>>>>>>>>>>  __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
>>>>>>>>>>>>>>  kasan_slab_alloc include/linux/kasan.h:253 [inline]
>>>>>>>>>>>>>>  slab_post_alloc_hook mm/slub.c:4569 [inline]
>>>>>>>>>>>>>>  slab_alloc_node mm/slub.c:4898 [inline]
>>>>>>>>>>>>>>  __do_kmalloc_node mm/slub.c:5294 [inline]
>>>>>>>>>>>>>>  __kvmalloc_node_noprof+0x4d7/0x8a0 mm/slub.c:6832
>>>>>>>>>>>>>>  seq_buf_alloc fs/seq_file.c:39 [inline]
>>>>>>>>>>>>>>  seq_read_iter+0x202/0xe10 fs/seq_file.c:211
>>>>>>>>>>>>>>  new_sync_read fs/read_write.c:493 [inline]
>>>>>>>>>>>>>>  vfs_read+0x582/0xa70 fs/read_write.c:574
>>>>>>>>>>>>>>  ksys_read+0x150/0x270 fs/read_write.c:717
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Memory state around the buggy address:
>>>>>>>>>>>>>>  ffff88816e172c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>>>>>>>>>>>>>>  ffff88816e172d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>>>>>>>>>>>>>> >ffff88816e172d80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>>>>>>>>>>>>>                    ^
>>>>>>>>>>>>>>  ffff88816e172e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>>>>>>>>>>>>>  ffff88816e172e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>>>>>>>>>>>>> ==================================================================
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ***
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> KASAN: slab-use-after-free Read in xfrm_dump_sa_done
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> tree:      net
>>>>>>>>>>>>>> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git
>>>>>>>>>>>>>> base:      18014147d3ee7831dce53fe65d7fc8d428b02552
>>>>>>>>>>>>>> arch:      amd64
>>>>>>>>>>>>>> compiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
>>>>>>>>>>>>>> config:    https://ci.syzbot.org/builds/90c5185d-0dad-4c34-a563-4253ebb12eb2/config
>>>>>>>>>>>>>> syz repro: https://ci.syzbot.org/findings/53579ff8-1479-4e0c-ae08-2f1ea756ee1b/syz_repro
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ==================================================================
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in xfrm_dump_sa_done+0x54/0xd0 net/xfrm/xfrm_user.c:1491
>>>>>>>>>>>>>> Read of size 8 at addr ffff888167305398 by task syz.0.17/5812
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> CPU: 1 UID: 0 PID: 5812 Comm: syz.0.17 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
>>>>>>>>>>>>>> Call Trace:
>>>>>>>>>>>>>>  <TASK>
>>>>>>>>>>>>>>  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
>>>>>>>>>>>>>>  xfrm_dump_sa_done+0x54/0xd0 net/xfrm/xfrm_user.c:1491
>>>>>>>>>>>>>>  netlink_release+0x12c8/0x1ad0 net/netlink/af_netlink.c:768
>>>>>>>>>>>>>>  __sock_release net/socket.c:722 [inline]
>>>>>>>>>>>>>>  sock_close+0xc3/0x240 net/socket.c:1514
>>>>>>>>>>>>>>  __fput+0x44f/0xa60 fs/file_table.c:510
>>>>>>>>>>>>>>  task_work_run+0x1d9/0x270 kernel/task_work.c:233
>>>>>>>>>>>>>>  resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
>>>>>>>>>>>>>>  __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
>>>>>>>>>>>>>>  exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98
>>>>>>>>>>>>>>  __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
>>>>>>>>>>>>>>  syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
>>>>>>>>>>>>>>  syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>> RIP: 0033:0x7fe50bf9ce59
>>>>>>>>>>>>>> Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
>>>>>>>>>>>>>> RSP: 002b:00007fff8a02cc38 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
>>>>>>>>>>>>>> RAX: 0000000000000000 RBX: 00007fe50c217da0 RCX: 00007fe50bf9ce59
>>>>>>>>>>>>>> RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
>>>>>>>>>>>>>> RBP: 00007fe50c217da0 R08: 00007fe50c216038 R09: 0000000000000000
>>>>>>>>>>>>>> R10: 000000000003fdd4 R11: 0000000000000246 R12: 0000000000010018
>>>>>>>>>>>>>> R13: 00007fe50c215fac R14: 00007fe50c215fa8 R15: 00007fe50c215fa0
>>>>>>>>>>>>>>  </TASK>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Allocated by task 5813:
>>>>>>>>>>>>>>  kasan_save_stack mm/kasan/common.c:57 [inline]
>>>>>>>>>>>>>>  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
>>>>>>>>>>>>>>  unpoison_slab_object mm/kasan/common.c:340 [inline]
>>>>>>>>>>>>>>  __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
>>>>>>>>>>>>>>  kasan_slab_alloc include/linux/kasan.h:253 [inline]
>>>>>>>>>>>>>>  slab_post_alloc_hook mm/slub.c:4569 [inline]
>>>>>>>>>>>>>>  slab_alloc_node mm/slub.c:4898 [inline]
>>>>>>>>>>>>>>  kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4950
>>>>>>>>>>>>>>  __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
>>>>>>>>>>>>>>  netlink_sendmsg+0x5d4/0xb40 net/netlink/af_netlink.c:1869
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
>>>>>>>>>>>>>>  ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
>>>>>>>>>>>>>>  __sys_sendmsg net/socket.c:2784 [inline]
>>>>>>>>>>>>>>  __do_sys_sendmsg net/socket.c:2789 [inline]
>>>>>>>>>>>>>>  __se_sys_sendmsg net/socket.c:2787 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Freed by task 5813:
>>>>>>>>>>>>>>  kasan_save_stack mm/kasan/common.c:57 [inline]
>>>>>>>>>>>>>>  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
>>>>>>>>>>>>>>  kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
>>>>>>>>>>>>>>  poison_slab_object mm/kasan/common.c:253 [inline]
>>>>>>>>>>>>>>  __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
>>>>>>>>>>>>>>  kasan_slab_free include/linux/kasan.h:235 [inline]
>>>>>>>>>>>>>>  slab_free_hook mm/slub.c:2689 [inline]
>>>>>>>>>>>>>>  slab_free mm/slub.c:6250 [inline]
>>>>>>>>>>>>>>  kmem_cache_free+0x182/0x650 mm/slub.c:6377
>>>>>>>>>>>>>>  netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
>>>>>>>>>>>>>>  netlink_unicast+0x764/0x8e0 net/netlink/af_netlink.c:1344
>>>>>>>>>>>>>>  netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
>>>>>>>>>>>>>>  ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
>>>>>>>>>>>>>>  __sys_sendmsg net/socket.c:2784 [inline]
>>>>>>>>>>>>>>  __do_sys_sendmsg net/socket.c:2789 [inline]
>>>>>>>>>>>>>>  __se_sys_sendmsg net/socket.c:2787 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The buggy address belongs to the object at ffff888167305380
>>>>>>>>>>>>>>  which belongs to the cache skbuff_head_cache of size 240
>>>>>>>>>>>>>> The buggy address is located 24 bytes inside of
>>>>>>>>>>>>>>  freed 240-byte region [ffff888167305380, ffff888167305470)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The buggy address belongs to the physical page:
>>>>>>>>>>>>>> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x167304
>>>>>>>>>>>>>> head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
>>>>>>>>>>>>>> flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
>>>>>>>>>>>>>> page_type: f5(slab)
>>>>>>>>>>>>>> raw: 057ff00000000040 ffff888160416dc0 dead000000000100 dead000000000122
>>>>>>>>>>>>>> raw: 0000000000000000 0000000800150015 00000000f5000000 0000000000000000
>>>>>>>>>>>>>> head: 057ff00000000040 ffff888160416dc0 dead000000000100 dead000000000122
>>>>>>>>>>>>>> head: 0000000000000000 0000000800150015 00000000f5000000 0000000000000000
>>>>>>>>>>>>>> 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5813, tgid 5812 (syz.0.17), ts 64859679564, free_ts 63312613640
>>>>>>>>>>>>>>  set_page_owner include/linux/page_owner.h:32 [inline]
>>>>>>>>>>>>>>  post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1858
>>>>>>>>>>>>>>  prep_new_page mm/page_alloc.c:1866 [inline]
>>>>>>>>>>>>>>  get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
>>>>>>>>>>>>>>  __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
>>>>>>>>>>>>>>  alloc_slab_page mm/slub.c:3278 [inline]
>>>>>>>>>>>>>>  allocate_slab+0x77/0x660 mm/slub.c:3467
>>>>>>>>>>>>>>  new_slab mm/slub.c:3525 [inline]
>>>>>>>>>>>>>>  refill_objects+0x339/0x3d0 mm/slub.c:7271
>>>>>>>>>>>>>>  refill_sheaf mm/slub.c:2816 [inline]
>>>>>>>>>>>>>>  __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
>>>>>>>>>>>>>>  alloc_from_pcs mm/slub.c:4749 [inline]
>>>>>>>>>>>>>>  slab_alloc_node mm/slub.c:4883 [inline]
>>>>>>>>>>>>>>  kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4950
>>>>>>>>>>>>>>  __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
>>>>>>>>>>>>>>  netlink_sendmsg+0x5d4/0xb40 net/netlink/af_netlink.c:1869
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
>>>>>>>>>>>>>>  ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
>>>>>>>>>>>>>>  __sys_sendmsg net/socket.c:2784 [inline]
>>>>>>>>>>>>>>  __do_sys_sendmsg net/socket.c:2789 [inline]
>>>>>>>>>>>>>>  __se_sys_sendmsg net/socket.c:2787 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>> page last free pid 15 tgid 15 stack trace:
>>>>>>>>>>>>>>  reset_page_owner include/linux/page_owner.h:25 [inline]
>>>>>>>>>>>>>>  __free_pages_prepare mm/page_alloc.c:1402 [inline]
>>>>>>>>>>>>>>  __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
>>>>>>>>>>>>>>  rcu_do_batch kernel/rcu/tree.c:2617 [inline]
>>>>>>>>>>>>>>  rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
>>>>>>>>>>>>>>  handle_softirqs+0x22a/0x840 kernel/softirq.c:622
>>>>>>>>>>>>>>  run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076
>>>>>>>>>>>>>>  smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
>>>>>>>>>>>>>>  kthread+0x389/0x470 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
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Memory state around the buggy address:
>>>>>>>>>>>>>>  ffff888167305280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
>>>>>>>>>>>>>>  ffff888167305300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>>>>>>>>>>>>>> >ffff888167305380: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>>>>>>>>>>>>>                             ^
>>>>>>>>>>>>>>  ffff888167305400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
>>>>>>>>>>>>>>  ffff888167305480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>>>>>>>>>>>>>> ==================================================================
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ***
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> KASAN: slab-use-after-free Write in sk_skb_reason_drop
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> tree:      net
>>>>>>>>>>>>>> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git
>>>>>>>>>>>>>> base:      18014147d3ee7831dce53fe65d7fc8d428b02552
>>>>>>>>>>>>>> arch:      amd64
>>>>>>>>>>>>>> compiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
>>>>>>>>>>>>>> config:    https://ci.syzbot.org/builds/90c5185d-0dad-4c34-a563-4253ebb12eb2/config
>>>>>>>>>>>>>> syz repro: https://ci.syzbot.org/findings/c87569e1-d26e-4670-a17b-9f2f64a5af67/syz_repro
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ==================================================================
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in __refcount_sub_and_test include/linux/refcount.h:389 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in __refcount_dec_and_test include/linux/refcount.h:432 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in refcount_dec_and_test include/linux/refcount.h:450 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in skb_unref include/linux/skbuff.h:1292 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in __sk_skb_reason_drop net/core/skbuff.c:1212 [inline]
>>>>>>>>>>>>>> BUG: KASAN: slab-use-after-free in sk_skb_reason_drop+0x37/0x110 net/core/skbuff.c:1240
>>>>>>>>>>>>>> Write of size 4 at addr ffff8881178efee4 by task syz.1.18/5873
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> CPU: 0 UID: 0 PID: 5873 Comm: syz.1.18 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
>>>>>>>>>>>>>> Call Trace:
>>>>>>>>>>>>>>  <TASK>
>>>>>>>>>>>>>>  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_write include/linux/instrumented.h:112 [inline]
>>>>>>>>>>>>>>  atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
>>>>>>>>>>>>>>  __refcount_sub_and_test include/linux/refcount.h:389 [inline]
>>>>>>>>>>>>>>  __refcount_dec_and_test include/linux/refcount.h:432 [inline]
>>>>>>>>>>>>>>  refcount_dec_and_test include/linux/refcount.h:450 [inline]
>>>>>>>>>>>>>>  skb_unref include/linux/skbuff.h:1292 [inline]
>>>>>>>>>>>>>>  __sk_skb_reason_drop net/core/skbuff.c:1212 [inline]
>>>>>>>>>>>>>>  sk_skb_reason_drop+0x37/0x110 net/core/skbuff.c:1240
>>>>>>>>>>>>>>  kfree_skb_reason include/linux/skbuff.h:1322 [inline]
>>>>>>>>>>>>>>  kfree_skb include/linux/skbuff.h:1331 [inline]
>>>>>>>>>>>>>>  netlink_release+0x133a/0x1ad0 net/netlink/af_netlink.c:770
>>>>>>>>>>>>>>  __sock_release net/socket.c:722 [inline]
>>>>>>>>>>>>>>  sock_close+0xc3/0x240 net/socket.c:1514
>>>>>>>>>>>>>>  __fput+0x44f/0xa60 fs/file_table.c:510
>>>>>>>>>>>>>>  task_work_run+0x1d9/0x270 kernel/task_work.c:233
>>>>>>>>>>>>>>  resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
>>>>>>>>>>>>>>  __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
>>>>>>>>>>>>>>  exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98
>>>>>>>>>>>>>>  __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
>>>>>>>>>>>>>>  syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
>>>>>>>>>>>>>>  syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>> RIP: 0033:0x7fd4d139ce59
>>>>>>>>>>>>>> Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
>>>>>>>>>>>>>> RSP: 002b:00007fff722ecbf8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
>>>>>>>>>>>>>> RAX: 0000000000000000 RBX: 00007fff722ecce0 RCX: 00007fd4d139ce59
>>>>>>>>>>>>>> RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
>>>>>>>>>>>>>> RBP: 0000000000012825 R08: 0000000000000001 R09: 0000000000000000
>>>>>>>>>>>>>> R10: 0000001b32e20000 R11: 0000000000000246 R12: 00007fff722ecd20
>>>>>>>>>>>>>> R13: 00007fd4d1615fac R14: 0000000000012859 R15: 00007fd4d1615fa0
>>>>>>>>>>>>>>  </TASK>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Allocated by task 5874:
>>>>>>>>>>>>>>  kasan_save_stack mm/kasan/common.c:57 [inline]
>>>>>>>>>>>>>>  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
>>>>>>>>>>>>>>  unpoison_slab_object mm/kasan/common.c:340 [inline]
>>>>>>>>>>>>>>  __kasan_mempool_unpoison_object+0xa3/0x130 mm/kasan/common.c:564
>>>>>>>>>>>>>>  kasan_mempool_unpoison_object include/linux/kasan.h:391 [inline]
>>>>>>>>>>>>>>  napi_skb_cache_get+0x3c8/0x780 net/core/skbuff.c:306
>>>>>>>>>>>>>>  __alloc_skb+0x19a/0x7d0 net/core/skbuff.c:696
>>>>>>>>>>>>>>  netlink_sendmsg+0x5d4/0xb40 net/netlink/af_netlink.c:1869
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  __sys_sendto+0x672/0x710 net/socket.c:2265
>>>>>>>>>>>>>>  __do_sys_sendto net/socket.c:2272 [inline]
>>>>>>>>>>>>>>  __se_sys_sendto net/socket.c:2268 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendto+0xde/0x100 net/socket.c:2268
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Freed by task 5874:
>>>>>>>>>>>>>>  kasan_save_stack mm/kasan/common.c:57 [inline]
>>>>>>>>>>>>>>  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
>>>>>>>>>>>>>>  kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
>>>>>>>>>>>>>>  poison_slab_object mm/kasan/common.c:253 [inline]
>>>>>>>>>>>>>>  __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
>>>>>>>>>>>>>>  kasan_slab_free include/linux/kasan.h:235 [inline]
>>>>>>>>>>>>>>  slab_free_hook mm/slub.c:2689 [inline]
>>>>>>>>>>>>>>  slab_free mm/slub.c:6250 [inline]
>>>>>>>>>>>>>>  kmem_cache_free+0x182/0x650 mm/slub.c:6377
>>>>>>>>>>>>>>  netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
>>>>>>>>>>>>>>  netlink_unicast+0x764/0x8e0 net/netlink/af_netlink.c:1344
>>>>>>>>>>>>>>  netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  __sys_sendto+0x672/0x710 net/socket.c:2265
>>>>>>>>>>>>>>  __do_sys_sendto net/socket.c:2272 [inline]
>>>>>>>>>>>>>>  __se_sys_sendto net/socket.c:2268 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendto+0xde/0x100 net/socket.c:2268
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The buggy address belongs to the object at ffff8881178efe00
>>>>>>>>>>>>>>  which belongs to the cache skbuff_head_cache of size 240
>>>>>>>>>>>>>> The buggy address is located 228 bytes inside of
>>>>>>>>>>>>>>  freed 240-byte region [ffff8881178efe00, ffff8881178efef0)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The buggy address belongs to the physical page:
>>>>>>>>>>>>>> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1178ee
>>>>>>>>>>>>>> head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
>>>>>>>>>>>>>> flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
>>>>>>>>>>>>>> page_type: f5(slab)
>>>>>>>>>>>>>> raw: 017ff00000000040 ffff888160416c80 dead000000000122 0000000000000000
>>>>>>>>>>>>>> raw: 0000000000000000 0000000800150015 00000000f5000000 0000000000000000
>>>>>>>>>>>>>> head: 017ff00000000040 ffff888160416c80 dead000000000122 0000000000000000
>>>>>>>>>>>>>> head: 0000000000000000 0000000800150015 00000000f5000000 0000000000000000
>>>>>>>>>>>>>> head: 017ff00000000001 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5050, tgid 5050 (klogd), ts 75887265953, free_ts 75876344896
>>>>>>>>>>>>>>  set_page_owner include/linux/page_owner.h:32 [inline]
>>>>>>>>>>>>>>  post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1858
>>>>>>>>>>>>>>  prep_new_page mm/page_alloc.c:1866 [inline]
>>>>>>>>>>>>>>  get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
>>>>>>>>>>>>>>  __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
>>>>>>>>>>>>>>  alloc_slab_page mm/slub.c:3278 [inline]
>>>>>>>>>>>>>>  allocate_slab+0x77/0x660 mm/slub.c:3467
>>>>>>>>>>>>>>  new_slab mm/slub.c:3525 [inline]
>>>>>>>>>>>>>>  refill_objects+0x339/0x3d0 mm/slub.c:7271
>>>>>>>>>>>>>>  refill_sheaf mm/slub.c:2816 [inline]
>>>>>>>>>>>>>>  __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
>>>>>>>>>>>>>>  alloc_from_pcs mm/slub.c:4749 [inline]
>>>>>>>>>>>>>>  slab_alloc_node mm/slub.c:4883 [inline]
>>>>>>>>>>>>>>  kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4950
>>>>>>>>>>>>>>  __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
>>>>>>>>>>>>>>  alloc_skb include/linux/skbuff.h:1383 [inline]
>>>>>>>>>>>>>>  alloc_skb_with_frags+0xc8/0x760 net/core/skbuff.c:6743
>>>>>>>>>>>>>>  sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2998
>>>>>>>>>>>>>>  unix_dgram_sendmsg+0x460/0x18d0 net/unix/af_unix.c:2141
>>>>>>>>>>>>>>  sock_sendmsg_nosec net/socket.c:787 [inline]
>>>>>>>>>>>>>>  __sock_sendmsg net/socket.c:802 [inline]
>>>>>>>>>>>>>>  __sys_sendto+0x672/0x710 net/socket.c:2265
>>>>>>>>>>>>>>  __do_sys_sendto net/socket.c:2272 [inline]
>>>>>>>>>>>>>>  __se_sys_sendto net/socket.c:2268 [inline]
>>>>>>>>>>>>>>  __x64_sys_sendto+0xde/0x100 net/socket.c:2268
>>>>>>>>>>>>>>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>>>>>>>>>>>>>>  do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
>>>>>>>>>>>>>>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>>>>>>>>>>>>> page last free pid 0 tgid 0 stack trace:
>>>>>>>>>>>>>>  reset_page_owner include/linux/page_owner.h:25 [inline]
>>>>>>>>>>>>>>  __free_pages_prepare mm/page_alloc.c:1402 [inline]
>>>>>>>>>>>>>>  __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
>>>>>>>>>>>>>>  rcu_do_batch kernel/rcu/tree.c:2617 [inline]
>>>>>>>>>>>>>>  rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
>>>>>>>>>>>>>>  handle_softirqs+0x22a/0x840 kernel/softirq.c:622
>>>>>>>>>>>>>>  __do_softirq kernel/softirq.c:656 [inline]
>>>>>>>>>>>>>>  invoke_softirq kernel/softirq.c:496 [inline]
>>>>>>>>>>>>>>  __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
>>>>>>>>>>>>>>  irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
>>>>>>>>>>>>>>  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
>>>>>>>>>>>>>>  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
>>>>>>>>>>>>>>  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Memory state around the buggy address:
>>>>>>>>>>>>>>  ffff8881178efd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>>>>>>>>>>>>>>  ffff8881178efe00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>>>>>>>>>>>>> >ffff8881178efe80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
>>>>>>>>>>>>>>                                                        ^
>>>>>>>>>>>>>>  ffff8881178eff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>>>>>>>>>>>>>>  ffff8881178eff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>>>>>>>>>>>>>> ==================================================================
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ***
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> If these findings have caused you to resend the series or submit a
>>>>>>>>>>>>>> separate fix, please add the following tag to your commit message:
>>>>>>>>>>>>>>   Tested-by: syzbot@syzkaller.appspotmail.com
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ---
>>>>>>>>>>>>>> This report is generated by a bot. It may contain errors.
>>>>>>>>>>>>>> syzbot ci engineers can be reached at syzkaller@googlegroups.com.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> To test a patch for this bug, please reply with `#syz test`
>>>>>>>>>>>>>> (should be on a separate line).
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The patch should be attached to the email.
>>>>>>>>>>>>>> Note: arguments like custom git repos and branches are not supported.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The email will later be sent to:
>>>>>>>>>>>>>> [davem@davemloft.net edumazet@google.com horms@kernel.org kees@kernel.org kuba@kernel.org kuniyu@google.com linux-kernel@vger.kernel.org netdev@vger.kernel.org pabeni@redhat.com stable@vger.kernel.org vulab@iscas.ac.cn yangfeng@kylinos.cn]
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> If the report looks fine to you, reply with:
>>>>>>>>>>>>>> #syz upstream
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> If the report is a false positive, reply with
>>>>>>>>>>>>>> #syz invalid
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
>>>>>>>>>>>>>> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-upstream-moderation+unsubscribe@googlegroups.com.
>>>>>>>>>>>>>> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/6a185386.99a1ea37.128423.0001.GAE%40google.com.
>>>>>>>>>>>>
>>>>>>>>>>>> -- 
>>>>>>>>>>>> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
>>>>>>>>>>>> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-upstream-moderation+unsubscribe@googlegroups.com.
>>>>>>>>>>>> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/6a18555e.e783d627.6395.0001.GAE%40google.com.
>>>>>>>>>>>
>>>>>>>>>>> I see the command but can't find the corresponding bug.
>>>>>>>>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>>>>>>>>> but the HASH does not correspond to any known bug.
>>>>>>>>>>> Please double check the address.
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> I see the command but can't find the corresponding bug.
>>>>>>>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>>>>>>>> but the HASH does not correspond to any known bug.
>>>>>>>>>> Please double check the address.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I see the command but can't find the corresponding bug.
>>>>>>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>>>>>>> but the HASH does not correspond to any known bug.
>>>>>>>>> Please double check the address.
>>>>>>>>>
>>>>>>>>> -- 
>>>>>>>>> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
>>>>>>>>> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-upstream-moderation+unsubscribe@googlegroups.com.
>>>>>>>>> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/6a185562.222db38e.c0a93.0000.GAE%40google.com.
>>>>>>>>
>>>>>>>> I see the command but can't find the corresponding bug.
>>>>>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>>>>>> but the HASH does not correspond to any known bug.
>>>>>>>> Please double check the address.
>>>>>>>>
>>>>>>>
>>>>>>> I see the command but can't find the corresponding bug.
>>>>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>>>>> but the HASH does not correspond to any known bug.
>>>>>>> Please double check the address.
>>>>>>>
>>>>>>
>>>>>> I see the command but can't find the corresponding bug.
>>>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>>>> but the HASH does not correspond to any known bug.
>>>>>> Please double check the address.
>>>>>>
>>>>>
>>>>> I see the command but can't find the corresponding bug.
>>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>>> but the HASH does not correspond to any known bug.
>>>>> Please double check the address.
>>>>>
>>>>
>>>> I see the command but can't find the corresponding bug.
>>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>>> but the HASH does not correspond to any known bug.
>>>> Please double check the address.
>>>>
>>>
>>> I see the command but can't find the corresponding bug.
>>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>>> but the HASH does not correspond to any known bug.
>>> Please double check the address.
>>>
>>
>> I see the command but can't find the corresponding bug.
>> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
>> but the HASH does not correspond to any known bug.
>> Please double check the address.
>>
>
> I see the command but can't find the corresponding bug.
> The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
> but the HASH does not correspond to any known bug.
> Please double check the address.
>
> -- 
> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-upstream-moderation+unsubscribe@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/6a18556a.9efe2910.1869e6.0016.GAE%40google.com.

I see the command but can't find the corresponding bug.
The email is sent to  syzbot+HASH@syzkaller.appspotmail.com address
but the HASH does not correspond to any known bug.
Please double check the address.