==================================================================
BUG: KASAN: slab-use-after-free in msg_word net/tipc/msg.h:207 [inline]
BUG: KASAN: slab-use-after-free in msg_bits net/tipc/msg.h:217 [inline]
BUG: KASAN: slab-use-after-free in msg_type net/tipc/msg.h:382 [inline]
BUG: KASAN: slab-use-after-free in tipc_skb_dump+0x12dd/0x17e0 net/tipc/trace.c:97
Read of size 4 at addr ffff888121907c34 by task syz.3.2692/7475

CPU: 0 UID: 0 PID: 7475 Comm: syz.3.2692 Not tainted syzkaller #0 ffcc03b7087851531ca4478bc989862769751c2e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 print_address_description+0x71/0x210 mm/kasan/report.c:377
 print_report+0x4a/0x70 mm/kasan/report.c:481
 kasan_report+0x162/0x1a0 mm/kasan/report.c:594
 __asan_report_load4_noabort+0x18/0x20 mm/kasan/report_generic.c:380
 msg_word net/tipc/msg.h:207 [inline]
 msg_bits net/tipc/msg.h:217 [inline]
 msg_type net/tipc/msg.h:382 [inline]
 tipc_skb_dump+0x12dd/0x17e0 net/tipc/trace.c:97
 tipc_list_dump+0x22f/0x300 net/tipc/trace.c:187
 tipc_sk_dump+0xa16/0xfd0 net/tipc/socket.c:3998
 do_trace_event_raw_event_tipc_sk_class net/tipc/trace.h:205 [inline]
 trace_event_raw_event_tipc_sk_class+0x290/0x4d0 net/tipc/trace.h:188
 trace_tipc_sk_overlimit1 net/tipc/trace.h:241 [inline]
 tipc_sk_enqueue net/tipc/socket.c:2455 [inline]
 tipc_sk_rcv+0x165f/0x2c70 net/tipc/socket.c:2497
 tipc_node_xmit+0x346/0x10e0 net/tipc/node.c:1701
 __tipc_sendmsg+0x1b36/0x28a0 net/tipc/socket.c:1511
 tipc_sendmsg+0x59/0x90 net/tipc/socket.c:1399
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0x9a1/0xa00 net/socket.c:2583
 ___sys_sendmsg+0x2a6/0x370 net/socket.c:2637
 __sys_sendmmsg+0x292/0x490 net/socket.c:2726
 __do_sys_sendmmsg net/socket.c:2753 [inline]
 __se_sys_sendmmsg net/socket.c:2750 [inline]
 __x64_sys_sendmmsg+0xa4/0xc0 net/socket.c:2750
 x64_sys_call+0xfec/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fc815b9e159
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:00007fc816a74028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fc815e25fa0 RCX: 00007fc815b9e159
RDX: 04000000000001c0 RSI: 00002000000044c0 RDI: 0000000000000003
RBP: 00007fc815c3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc815e26038 R14: 00007fc815e25fa0 R15: 00007fffbbf45d08
 </TASK>

Allocated by task 7475:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 unpoison_slab_object mm/kasan/common.c:321 [inline]
 __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347
 kasan_slab_alloc include/linux/kasan.h:251 [inline]
 slab_post_alloc_hook mm/slub.c:4202 [inline]
 slab_alloc_node mm/slub.c:4251 [inline]
 kmem_cache_alloc_node_noprof+0x1ca/0x420 mm/slub.c:4305
 kmalloc_reserve+0xcf/0x4f0 net/core/skbuff.c:596
 __alloc_skb+0x13f/0x360 net/core/skbuff.c:687
 alloc_skb_fclone include/linux/skbuff.h:1413 [inline]
 tipc_buf_acquire net/tipc/msg.c:72 [inline]
 tipc_msg_build+0x160/0xf20 net/tipc/msg.c:402
 __tipc_sendmsg+0x1693/0x28a0 net/tipc/socket.c:1501
 tipc_sendmsg+0x59/0x90 net/tipc/socket.c:1399
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0x9a1/0xa00 net/socket.c:2583
 ___sys_sendmsg+0x2a6/0x370 net/socket.c:2637
 __sys_sendmmsg+0x292/0x490 net/socket.c:2726
 __do_sys_sendmmsg net/socket.c:2753 [inline]
 __se_sys_sendmmsg net/socket.c:2750 [inline]
 __x64_sys_sendmmsg+0xa4/0xc0 net/socket.c:2750
 x64_sys_call+0xfec/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 7474:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_free_info+0x44/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:249 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2445 [inline]
 slab_free mm/slub.c:4714 [inline]
 kfree+0x158/0x440 mm/slub.c:4875
 skb_kfree_head net/core/skbuff.c:1081 [inline]
 skb_free_head+0xf7/0x300 net/core/skbuff.c:1098
 skb_release_data+0x6d0/0x860 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1190 [inline]
 __kfree_skb+0x62/0x210 net/core/skbuff.c:1204
 sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1242
 kfree_skb_reason include/linux/skbuff.h:1303 [inline]
 kfree_skb include/linux/skbuff.h:1312 [inline]
 tipc_msg_reverse+0x1a8/0x950 net/tipc/msg.c:684
 tipc_sk_respond+0x139/0x430 net/tipc/socket.c:290
 tsk_rej_rx_queue net/tipc/socket.c:311 [inline]
 __tipc_shutdown+0x9b1/0x14e0 net/tipc/socket.c:575
 tipc_release+0xe0/0x1c40 net/tipc/socket.c:640
 __sock_release net/socket.c:641 [inline]
 sock_close+0xb4/0x220 net/socket.c:1408
 __fput+0x208/0xa30 fs/file_table.c:447
 ____fput+0x20/0x30 fs/file_table.c:475
 task_work_run+0x1e8/0x260 kernel/task_work.c:246
 resume_user_mode_work+0x35/0x50 include/linux/resume_user_mode.h:50
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x63/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff888121907b80
 which belongs to the cache skbuff_small_head of size 768
The buggy address is located 180 bytes inside of
 freed 768-byte region [ffff888121907b80, ffff888121907e80)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x121904
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4000000000000040(head|zone=1)
page_type: f5(slab)
raw: 4000000000000040 ffff888106e58b40 ffffea00045b0500 dead000000000004
raw: 0000000000000000 0000000000120012 00000001f5000000 0000000000000000
head: 4000000000000040 ffff888106e58b40 ffffea00045b0500 dead000000000004
head: 0000000000000000 0000000000120012 00000001f5000000 0000000000000000
head: 4000000000000002 ffffea0004864101 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 149, tgid 149 (dhcpcd), ts 18726588484, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1863
 prep_new_page+0x2d/0x180 mm/page_alloc.c:1871
 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3948
 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5315
 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1
 allocate_slab+0x69/0x430 mm/slub.c:2687
 new_slab mm/slub.c:2741 [inline]
 ___slab_alloc+0x591/0x8c0 mm/slub.c:3934
 __slab_alloc mm/slub.c:4025 [inline]
 __slab_alloc_node mm/slub.c:4078 [inline]
 slab_alloc_node mm/slub.c:4239 [inline]
 kmem_cache_alloc_node_noprof+0x29b/0x420 mm/slub.c:4305
 kmalloc_reserve+0xcf/0x4f0 net/core/skbuff.c:596
 __alloc_skb+0x13f/0x360 net/core/skbuff.c:687
 alloc_skb include/linux/skbuff.h:1363 [inline]
 netlink_alloc_large_skb+0xf7/0x1b0 net/netlink/af_netlink.c:1181
 netlink_sendmsg+0x576/0xad0 net/netlink/af_netlink.c:1865
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0x9a1/0xa00 net/socket.c:2583
 ___sys_sendmsg+0x2a6/0x370 net/socket.c:2637
 __sys_sendmsg net/socket.c:2669 [inline]
 __do_sys_sendmsg net/socket.c:2674 [inline]
 __se_sys_sendmsg net/socket.c:2672 [inline]
 __x64_sys_sendmsg+0x1be/0x2a0 net/socket.c:2672
 x64_sys_call+0x2a4c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:47
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888121907b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888121907b80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888121907c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888121907c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888121907d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================