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BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:1026 [inline]
BUG: KASAN: use-after-free in udp_tunnel_update_gro_lookup+0xfe/0x2c0 net/ipv4/udp_offload.c:60
Write of size 8 at addr ffff88805ef38730 by task syz.0.575/8058

CPU: 1 UID: 0 PID: 8058 Comm: syz.0.575 Not tainted 6.14.0-rc7-syzkaller-01431-gbfc17c165835 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 hlist_add_head include/linux/list.h:1026 [inline]
 udp_tunnel_update_gro_lookup+0xfe/0x2c0 net/ipv4/udp_offload.c:60
 rxrpc_open_socket net/rxrpc/local_object.c:197 [inline]
 rxrpc_lookup_local+0xea5/0x1890 net/rxrpc/local_object.c:293
 rxrpc_sendmsg+0x323/0x5f0 net/rxrpc/af_rxrpc.c:608
 sock_sendmsg_nosec net/socket.c:709 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:724
 ____sys_sendmsg+0x53a/0x860 net/socket.c:2564
 ___sys_sendmsg net/socket.c:2618 [inline]
 __sys_sendmsg+0x269/0x350 net/socket.c:2650
 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: 0033:0x7f0d93d8d169
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:00007f0d93bb7038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0d93fa6160 RCX: 00007f0d93d8d169
RDX: 0000000004048800 RSI: 0000200000000080 RDI: 000000000000000b
RBP: 00007f0d93e0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0d93fa6160 R15: 00007ffc6d894888
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805ef3f000 pfn:0x5ef38
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea0000cd9a08 ffffea00010b6a08 0000000000000000
raw: ffff88805ef3f000 0000000000000003 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7644, tgid 7643 (syz.4.460), ts 113142073000, free_ts 122780202371
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4740
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 copy_verifier_state+0x6f0/0xda0 kernel/bpf/verifier.c:1667
 is_state_visited kernel/bpf/verifier.c:18812 [inline]
 do_check+0x4612/0xfb10 kernel/bpf/verifier.c:18974
 do_check_common+0x1268/0x1bd0 kernel/bpf/verifier.c:22273
 do_check_main kernel/bpf/verifier.c:22364 [inline]
 bpf_check+0x5a44/0x1bcd0 kernel/bpf/verifier.c:23160
 bpf_prog_load+0x1664/0x20e0 kernel/bpf/syscall.c:2952
 __sys_bpf+0x4ea/0x820 kernel/bpf/syscall.c:5795
 __do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5900
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 8032 tgid 8030 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 __slab_free+0x2c2/0x380 mm/slub.c:4520
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/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:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_node_track_caller_noprof+0x237/0x4c0 mm/slub.c:4313
 __do_krealloc mm/slub.c:4820 [inline]
 krealloc_noprof+0x10f/0x300 mm/slub.c:4873
 kvrealloc_noprof+0x95/0x150 mm/util.c:759
 push_insn_history+0x16f/0x6b0 kernel/bpf/verifier.c:3753
 do_check+0x6a0e/0xfb10 kernel/bpf/verifier.c:18993
 do_check_common+0x1268/0x1bd0 kernel/bpf/verifier.c:22273
 do_check_main kernel/bpf/verifier.c:22364 [inline]
 bpf_check+0x5a44/0x1bcd0 kernel/bpf/verifier.c:23160
 bpf_prog_load+0x1664/0x20e0 kernel/bpf/syscall.c:2952
 __sys_bpf+0x4ea/0x820 kernel/bpf/syscall.c:5795
 __do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5900
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83

Memory state around the buggy address:
 ffff88805ef38600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805ef38680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805ef38700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                     ^
 ffff88805ef38780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805ef38800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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