==================================================================
BUG: KASAN: slab-use-after-free in __skb_insert include/linux/skbuff.h:2284 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_before include/linux/skbuff.h:2390 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_tail include/linux/skbuff.h:2423 [inline]
BUG: KASAN: slab-use-after-free in gro_cells_receive+0x51d/0x690 net/core/gro_cells.c:38
Write of size 8 at addr ffff888051e02640 by task syz.0.1505/7810

CPU: 0 UID: 0 PID: 7810 Comm: syz.0.1505 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 __skb_insert include/linux/skbuff.h:2284 [inline]
 __skb_queue_before include/linux/skbuff.h:2390 [inline]
 __skb_queue_tail include/linux/skbuff.h:2423 [inline]
 gro_cells_receive+0x51d/0x690 net/core/gro_cells.c:38
 ip6_tnl_rcv+0x7c/0xa0 net/ipv6/ip6_tunnel.c:903
 ip6gre_rcv net/ipv6/ip6_gre.c:-1 [inline]
 gre_rcv+0xbfa/0x11e0 net/ipv6/ip6_gre.c:588
 ip6_protocol_deliver_rcu+0xe0b/0x15c0 net/ipv6/ip6_input.c:438
 ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:489
 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:318
 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
 dst_input include/net/dst.h:471 [inline]
 ip6_sublist_rcv_finish+0x1c8/0x2a0 net/ipv6/ip6_input.c:88
 ip6_list_rcv_finish net/ipv6/ip6_input.c:145 [inline]
 ip6_sublist_rcv+0xb11/0xdd0 net/ipv6/ip6_input.c:321
 ipv6_list_rcv+0x3e5/0x430 net/ipv6/ip6_input.c:355
 __netif_receive_skb_list_ptype net/core/dev.c:6034 [inline]
 __netif_receive_skb_list_core+0x5f4/0x800 net/core/dev.c:6081
 __netif_receive_skb_list net/core/dev.c:6133 [inline]
 netif_receive_skb_list_internal+0x975/0xcc0 net/core/dev.c:6224
 netif_receive_skb_list+0x54/0x450 net/core/dev.c:6276
 xdp_recv_frames net/bpf/test_run.c:280 [inline]
 xdp_test_run_batch net/bpf/test_run.c:361 [inline]
 bpf_test_run_xdp_live+0x1786/0x1b10 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0x75b/0x10e0 net/bpf/test_run.c:1331
 bpf_prog_test_run+0x2ca/0x340 kernel/bpf/syscall.c:4673
 __sys_bpf+0x562/0x860 kernel/bpf/syscall.c:6152
 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6242 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f712238eec9
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:00007ffd316d1648 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f71225e5fa0 RCX: 00007f712238eec9
RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a
RBP: 00007f7122411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f71225e5fa0 R14: 00007f71225e5fa0 R15: 0000000000000003
 </TASK>

Allocated by task 7810:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:330 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 kmem_cache_alloc_bulk_noprof+0x519/0xb60 mm/slub.c:5426
 xdp_recv_frames net/bpf/test_run.c:260 [inline]
 xdp_test_run_batch net/bpf/test_run.c:361 [inline]
 bpf_test_run_xdp_live+0x15f1/0x1b10 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0x75b/0x10e0 net/bpf/test_run.c:1331
 bpf_prog_test_run+0x2ca/0x340 kernel/bpf/syscall.c:4673
 __sys_bpf+0x562/0x860 kernel/bpf/syscall.c:6152
 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6242 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 16:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2422 [inline]
 slab_free mm/slub.c:4695 [inline]
 kmem_cache_free+0x19a/0x640 mm/slub.c:4797
 kfree_skb_reason include/linux/skbuff.h:1275 [inline]
 __netif_receive_skb_core+0x3d5f/0x4380 net/core/dev.c:5965
 __netif_receive_skb_list_core+0x23f/0x800 net/core/dev.c:6066
 __netif_receive_skb_list net/core/dev.c:6133 [inline]
 netif_receive_skb_list_internal+0x975/0xcc0 net/core/dev.c:6224
 gro_normal_list include/net/gro.h:532 [inline]
 gro_normal_one include/net/gro.h:552 [inline]
 gro_skb_finish net/core/gro.c:601 [inline]
 gro_receive_skb+0x5be/0xbf0 net/core/gro.c:631
 napi_gro_receive include/linux/netdevice.h:4167 [inline]
 gro_cell_poll+0x148/0x1d0 net/core/gro_cells.c:61
 __napi_poll+0xb6/0x540 net/core/dev.c:7506
 napi_poll net/core/dev.c:7569 [inline]
 net_rx_action+0x707/0xe00 net/core/dev.c:7696
 handle_softirqs+0x22f/0x710 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888051e02640
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
 freed 240-byte region [ffff888051e02640, ffff888051e02730)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x51e02
flags: 0x80000000000000(node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000000 ffff88801ce87a00 dead000000000122 0000000000000000
raw: 0000000000000000 00000000000c000c 00000000f5000000 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 7810, tgid 7810 (syz.0.1505), ts 384690108866, free_ts 383786018073
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x26dc/0x2770 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2492 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2660
 new_slab mm/slub.c:2714 [inline]
 ___slab_alloc+0xab4/0x1320 mm/slub.c:3901
 __kmem_cache_alloc_bulk mm/slub.c:5346 [inline]
 kmem_cache_alloc_bulk_noprof+0x227/0xb60 mm/slub.c:5418
 xdp_recv_frames net/bpf/test_run.c:260 [inline]
 xdp_test_run_batch net/bpf/test_run.c:361 [inline]
 bpf_test_run_xdp_live+0x15f1/0x1b10 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0x75b/0x10e0 net/bpf/test_run.c:1331
 bpf_prog_test_run+0x2ca/0x340 kernel/bpf/syscall.c:4673
 __sys_bpf+0x562/0x860 kernel/bpf/syscall.c:6152
 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6242 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 7438 tgid 7438 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xfcf/0x1160 mm/page_alloc.c:2895
 discard_slab mm/slub.c:2758 [inline]
 __put_partials+0x159/0x1a0 mm/slub.c:3223
 __slab_free+0x2b3/0x390 mm/slub.c:4565
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_noprof+0x114/0x2d0 mm/slub.c:4247
 getname_flags+0xb8/0x540 fs/namei.c:146
 user_path_at+0x24/0x60 fs/namei.c:3214
 ksys_umount fs/namespace.c:2055 [inline]
 __do_sys_umount fs/namespace.c:2063 [inline]
 __se_sys_umount fs/namespace.c:2061 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2061
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888051e02500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888051e02580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
>ffff888051e02600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                                           ^
 ffff888051e02680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888051e02700: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
==================================================================