------------[ cut here ]------------
sk->sk_forward_alloc
WARNING: net/ipv4/af_inet.c:162 at inet_sock_destruct+0x62d/0x740 net/ipv4/af_inet.c:162, CPU#1: syz.3.2957/17029
Modules linked in:
CPU: 1 UID: 0 PID: 17029 Comm: syz.3.2957 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:inet_sock_destruct+0x62d/0x740 net/ipv4/af_inet.c:162
Code: 0f 0b 90 e9 58 fe ff ff e8 80 0c 9f f7 90 0f 0b 90 e9 8b fe ff ff e8 72 0c 9f f7 90 0f 0b 90 e9 b1 fe ff ff e8 64 0c 9f f7 90 <0f> 0b 90 e9 d7 fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 95 fc
RSP: 0018:ffffc90000a08d48 EFLAGS: 00010246
RAX: ffffffff8a26a20c RBX: dffffc0000000000 RCX: ffff88801db69e80
RDX: 0000000000000100 RSI: 0000000000000f70 RDI: 0000000000000000
RBP: 0000000000000f70 R08: ffff88802ac8f127 R09: 1ffff11005591e24
R10: dffffc0000000000 R11: ffffed1005591e25 R12: ffff88802ac8ee80
R13: dffffc0000000000 R14: ffff88802ac8f10c R15: ffffffff8fca6c80
FS:  00007fdb8f4906c0(0000) GS:ffff888125555000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f372a74da08 CR3: 00000000354d4000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __sk_destruct+0x85/0x880 net/core/sock.c:2350
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872
Code: e9 30 ff ff ff e8 45 65 0f 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 c1 22 7b 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d be 4f 73
RSP: 0018:ffffc90005ee78f0 EFLAGS: 00000296
RAX: 361d5b496295a000 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 00000000f55d60ce RSI: ffffffff8e19a76a RDI: ffffffff8c27ca80
RBP: 0000000000000001 R08: ffffffff82241bf8 R09: ffff8880b873f368
R10: dffffc0000000000 R11: ffffed100666cadb R12: 0000000000000000
R13: ffff8880b873f368 R14: 0000000000000000 R15: 0000000000000001
 local_trylock_acquire include/linux/local_lock_internal.h:53 [inline]
 alloc_from_pcs mm/slub.c:4711 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_noprof+0x1d4/0x760 mm/slub.c:5272
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 __netlink_kernel_create+0x1e3/0x720 net/netlink/af_netlink.c:2028
 netlink_kernel_create include/linux/netlink.h:62 [inline]
 nl_fib_lookup_init net/ipv4/fib_frontend.c:1439 [inline]
 fib_net_init+0x208/0x3b0 net/ipv4/fib_frontend.c:1645
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x118/0x340 net/core/net_namespace.c:446
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x51d/0x930 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3242
 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: 0033:0x7fdb8e59c799
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:00007fdb8f490028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fdb8e816180 RCX: 00007fdb8e59c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007fdb8e632c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb8e816218 R14: 00007fdb8e816180 R15: 00007ffe1a59cea8
 </TASK>
----------------
Code disassembly (best guess):
   0:	e9 30 ff ff ff       	jmp    0xffffff35
   5:	e8 45 65 0f 0a       	call   0xa0f654f
   a:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  10:	0f 84 38 ff ff ff    	je     0xffffff4e
  16:	65 48 8b 05 c1 22 7b 	mov    %gs:0x117b22c1(%rip),%rax        # 0x117b22df
  1d:	11
  1e:	48 3b 44 24 30       	cmp    0x30(%rsp),%rax
  23:	75 33                	jne    0x58
  25:	fb                   	sti
  26:	48 83 c4 38          	add    $0x38,%rsp
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	41 5c                	pop    %r12
  2d:	41 5d                	pop    %r13
  2f:	41 5e                	pop    %r14
  31:	41 5f                	pop    %r15
  33:	5d                   	pop    %rbp
  34:	c3                   	ret
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	48                   	rex.W
  3b:	8d                   	.byte 0x8d
  3c:	3d                   	.byte 0x3d
  3d:	be                   	.byte 0xbe
  3e:	4f                   	rex.WRXB
  3f:	73                   	.byte 0x73