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BUG: KASAN: use-after-free in read_pnet include/net/net_namespace.h:419 [inline]
BUG: KASAN: use-after-free in dev_net include/linux/netdevice.h:2741 [inline]
BUG: KASAN: use-after-free in nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319
Read of size 8 at addr ffff8880544c4108 by task syz.0.793/8655

CPU: 1 UID: 0 PID: 8655 Comm: syz.0.793 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 read_pnet include/net/net_namespace.h:419 [inline]
 dev_net include/linux/netdevice.h:2741 [inline]
 nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319
 __nf_unregister_net_hook+0x74/0x6f0 net/netfilter/core.c:491
 nft_unregister_flowtable_ops net/netfilter/nf_tables_api.c:8895 [inline]
 __nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8910 [inline]
 nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8922 [inline]
 nf_tables_commit+0x4270/0xa400 net/netfilter/nf_tables_api.c:11081
 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:576 [inline]
 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:649 [inline]
 nfnetlink_rcv+0x1c1b/0x27b0 net/netfilter/nfnetlink.c:667
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda6659c799
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:00007fda6742a028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fda66815fa0 RCX: 00007fda6659c799
RDX: 0000000004000000 RSI: 0000200000000340 RDI: 0000000000000003
RBP: 00007fda66632bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda66816038 R14: 00007fda66815fa0 R15: 00007fda6693fa48
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880544c7c00 pfn:0x544c4
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000170d808 ffffea00016a3c08 0000000000000000
raw: ffff8880544c7c00 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 8247, tgid 8246 (syz.2.661), ts 284377252011, free_ts 301426513422
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2484
 alloc_slab_page mm/slub.c:3267 [inline]
 allocate_slab+0x83/0x660 mm/slub.c:3458
 new_slab mm/slub.c:3516 [inline]
 ___slab_alloc+0x150/0x6b0 mm/slub.c:4390
 __slab_alloc_node mm/slub.c:4456 [inline]
 slab_alloc_node mm/slub.c:4832 [inline]
 __kmalloc_cache_noprof+0x12e/0x660 mm/slub.c:5353
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 genradix_alloc_node include/linux/generic-radix-tree.h:101 [inline]
 __genradix_ptr_alloc+0x352/0x4a0 lib/generic-radix-tree.c:69
 __genradix_prealloc+0x44/0x90 lib/generic-radix-tree.c:216
 sctp_stream_alloc_in net/sctp/stream.c:121 [inline]
 sctp_process_strreset_addstrm_out+0x294/0x700 net/sctp/stream.c:810
 sctp_sf_do_reconf+0x695/0xab0 net/sctp/sm_statefuns.c:4170
 sctp_do_sm+0x238/0x5cf0 net/sctp/sm_sideeffect.c:1172
 sctp_assoc_bh_rcv+0x3f2/0x630 net/sctp/associola.c:1034
 sctp_backlog_rcv+0x167/0x380 net/sctp/input.c:331
 sk_backlog_rcv include/net/sock.h:1185 [inline]
 __release_sock+0x297/0x3a0 net/core/sock.c:3213
 release_sock+0x5f/0x1f0 net/core/sock.c:3795
page last free pid 26 tgid 26 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
 __slab_free+0x263/0x2b0 mm/slub.c:5551
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 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:4515 [inline]
 slab_alloc_node mm/slub.c:4844 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4851
 alloc_filename fs/namei.c:142 [inline]
 do_getname_kernel+0x54/0x230 fs/namei.c:261
 getname_kernel fs/namei.c:284 [inline]
 class_filename_kernel_constructor include/linux/fs.h:2540 [inline]
 start_removing_path+0x23/0x150 fs/namei.c:3024
 handle_remove drivers/base/devtmpfs.c:325 [inline]
 handle drivers/base/devtmpfs.c:386 [inline]
 devtmpfs_work_loop+0x245/0xdf0 drivers/base/devtmpfs.c:399
 devtmpfsd+0x4d/0x50 drivers/base/devtmpfs.c:441
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 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:
 ffff8880544c4000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880544c4080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880544c4100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff8880544c4180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880544c4200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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