syzbot

==================================================================
BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:384 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler+0x882/0x9c0 net/ipv4/tcp_timer.c:663
Read of size 1 at addr ffff888077fa868d by task kworker/0:7/3648

CPU: 0 PID: 3648 Comm: kworker/0:7 Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: rcu_gp process_srcu
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 tcp_probe_timer net/ipv4/tcp_timer.c:384 [inline]
 tcp_write_timer_handler+0x882/0x9c0 net/ipv4/tcp_timer.c:663
 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:679
 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:193
Code: 1f 84 00 00 00 00 00 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 08 ed 68 0c 48 89 de 5b e9 c7 fc 48 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d 54 0e 82 7e 65 8b 15 55 0e 82 7e f7 c2 00
RSP: 0000:ffffc90003147ad8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff914d29d0 RCX: ffff888024fd8000
RDX: ffff888024fd8000 RSI: 00000000ffffffff RDI: 00000000ffffffff
RBP: 000000000000b9a4 R08: ffffffff842b916e R09: fffff52000628f2d
R10: 0000000000000000 R11: dffffc0000000001 R12: 000000000000b9a3
R13: 1ffffffff1bd29c7 R14: ffffffff8de94c38 R15: 00000000ffffffff
 cpumask_next+0x61/0xf0 lib/cpumask.c:20
 srcu_readers_unlock_idx kernel/rcu/srcutree.c:266 [inline]
 srcu_readers_active_idx_check kernel/rcu/srcutree.c:282 [inline]
 try_check_zero+0x6b/0x360 kernel/rcu/srcutree.c:698
 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline]
 process_srcu+0x1aa/0xc20 kernel/rcu/srcutree.c:1325
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 3570:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 net_alloc net/core/net_namespace.c:408 [inline]
 copy_net_ns+0x140/0x5d0 net/core/net_namespace.c:463
 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226
 ksys_unshare+0x580/0xb20 kernel/fork.c:3101
 __do_sys_unshare kernel/fork.c:3175 [inline]
 __se_sys_unshare kernel/fork.c:3173 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3173
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888077fa8000
 which belongs to the cache net_namespace of size 6528
The buggy address is located 1677 bytes inside of
 6528-byte region [ffff888077fa8000, ffff888077fa9980)
The buggy address belongs to the page:
page:ffffea0001dfea00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888077fa8000 pfn:0x77fa8
head:ffffea0001dfea00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88806121fd81
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001dfac00 0000000200000002 ffff888011df23c0
raw: ffff888077fa8000 0000000080040002 00000001ffffffff ffff88806121fd81
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3570, ts 42138737917, free_ts 42104895216
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 net_alloc net/core/net_namespace.c:408 [inline]
 copy_net_ns+0x140/0x5d0 net/core/net_namespace.c:463
 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226
 ksys_unshare+0x580/0xb20 kernel/fork.c:3101
 __do_sys_unshare kernel/fork.c:3175 [inline]
 __se_sys_unshare kernel/fork.c:3173 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3173
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 free_slab mm/slub.c:2015 [inline]
 discard_slab mm/slub.c:2021 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507
 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587
 do_slab_free mm/slub.c:3487 [inline]
 ___cache_free+0xe3/0x100 mm/slub.c:3506
 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 __kmalloc_node+0x151/0x390 mm/slub.c:4451
 kmalloc_node include/linux/slab.h:614 [inline]
 kvmalloc_node+0x80/0x140 mm/util.c:619
 kvmalloc include/linux/mm.h:805 [inline]
 kvzalloc include/linux/mm.h:813 [inline]
 proc_sys_call_handler+0x3d0/0x8a0 fs/proc/proc_sysctl.c:570
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacd/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff888077fa8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888077fa8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888077fa8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888077fa8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888077fa8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	84 00                	test   %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	0f 1f 00             	nopl   (%rax)
   9:	53                   	push   %rbx
   a:	48 89 fb             	mov    %rdi,%rbx
   d:	e8 17 00 00 00       	call   0x29
  12:	48 8b 3d 08 ed 68 0c 	mov    0xc68ed08(%rip),%rdi        # 0xc68ed21
  19:	48 89 de             	mov    %rbx,%rsi
  1c:	5b                   	pop    %rbx
  1d:	e9 c7 fc 48 00       	jmp    0x48fce9
  22:	cc                   	int3
  23:	cc                   	int3
  24:	cc                   	int3
  25:	cc                   	int3
  26:	cc                   	int3
  27:	cc                   	int3
  28:	cc                   	int3
* 29:	48 8b 04 24          	mov    (%rsp),%rax <-- trapping instruction
  2d:	65 48 8b 0d 54 0e 82 	mov    %gs:0x7e820e54(%rip),%rcx        # 0x7e820e89
  34:	7e
  35:	65 8b 15 55 0e 82 7e 	mov    %gs:0x7e820e55(%rip),%edx        # 0x7e820e91
  3c:	f7                   	.byte 0xf7
  3d:	c2                   	.byte 0xc2