==================================================================
BUG: KASAN: use-after-free in __tcp_mtu_to_mss+0x361/0x3a0 net/ipv4/tcp_output.c:1722
Read of size 4 at addr ffff8880235d3aec by task kworker/u4:6/7526
CPU: 0 PID: 7526 Comm: kworker/u4:6 Not tainted 5.15.117-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: netns cleanup_net
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb 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_mtu_to_mss+0x361/0x3a0 net/ipv4/tcp_output.c:1722
tcp_mtu_to_mss net/ipv4/tcp_output.c:1731 [inline]
tcp_sync_mss net/ipv4/tcp_output.c:1807 [inline]
tcp_current_mss+0x274/0x670 net/ipv4/tcp_output.c:1837
tcp_send_loss_probe+0x28/0x8e0 net/ipv4/tcp_output.c:2806
tcp_write_timer_handler+0x381/0x9c0 net/ipv4/tcp_timer.c:622
tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:646
call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421
expire_timers kernel/time/timer.c:1466 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1737
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750
__do_softirq+0x3b3/0x93a kernel/softirq.c:558
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x155/0x240 kernel/softirq.c:636
irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
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:__rcu_read_lock+0x4c/0xb0 kernel/rcu/tree_plugin.h:400
Code: 48 c1 eb 03 42 0f b6 04 33 84 c0 75 2f 41 8b 2f ff c5 42 0f b6 04 33 84 c0 75 38 41 89 2f 42 0f b6 04 33 84 c0 75 43 41 8b 07 <3d> 00 00 00 40 7d 07 5b 41 5e 41 5f 5d c3 0f 0b eb f5 44 89 f9 80
RSP: 0018:ffffc90004507a38 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff11009df4087 RCX: ffff88804efa0000
RDX: ffff88804efa0000 RSI: ffffffff8a8b0f00 RDI: ffffffff8ad86000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1bc7886
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88814b3239f8
R13: 1ffffffff1b77814 R14: dffffc0000000000 R15: ffff88804efa043c
rcu_read_lock include/linux/rcupdate.h:694 [inline]
inet_twsk_purge+0x119/0xa20 net/ipv4/inet_timewait_sock.c:268
ops_exit_list net/core/net_namespace.c:174 [inline]
cleanup_net+0x763/0xb60 net/core/net_namespace.c:596
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
kthread+0x3f6/0x4f0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
Allocated by task 9808:
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:405 [inline]
copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460
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:3094
__do_sys_unshare kernel/fork.c:3168 [inline]
__se_sys_unshare kernel/fork.c:3166 [inline]
__x64_sys_unshare+0x34/0x40 kernel/fork.c:3166
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
The buggy address belongs to the object at ffff8880235d3480
which belongs to the cache net_namespace of size 6464
The buggy address is located 1644 bytes inside of
6464-byte region [ffff8880235d3480, ffff8880235d4dc0)
The buggy address belongs to the page:
page:ffffea00008d7400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880235d3480 pfn:0x235d0
head:ffffea00008d7400 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff8880236652c1
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888011dc63c0
raw: ffff8880235d3480 0000000080040003 00000001ffffffff ffff8880236652c1
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 3524, ts 89432830654, free_ts 89398087768
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:5421
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:405 [inline]
copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460
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:3094
__do_sys_unshare kernel/fork.c:3168 [inline]
__se_sys_unshare kernel/fork.c:3166 [inline]
__x64_sys_unshare+0x34/0x40 kernel/fork.c:3166
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
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]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
skb_clone+0x1bb/0x350 net/core/skbuff.c:1523
hci_event_packet+0x370/0x1480 net/bluetooth/hci_event.c:6331
hci_rx_work+0x240/0x7d0 net/bluetooth/hci_core.c:5153
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
kthread+0x3f6/0x4f0 kernel/kthread.c:319
Memory state around the buggy address:
ffff8880235d3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880235d3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880235d3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880235d3b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880235d3b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 48 c1 eb 03 shr $0x3,%rbx
4: 42 0f b6 04 33 movzbl (%rbx,%r14,1),%eax
9: 84 c0 test %al,%al
b: 75 2f jne 0x3c
d: 41 8b 2f mov (%r15),%ebp
10: ff c5 inc %ebp
12: 42 0f b6 04 33 movzbl (%rbx,%r14,1),%eax
17: 84 c0 test %al,%al
19: 75 38 jne 0x53
1b: 41 89 2f mov %ebp,(%r15)
1e: 42 0f b6 04 33 movzbl (%rbx,%r14,1),%eax
23: 84 c0 test %al,%al
25: 75 43 jne 0x6a
27: 41 8b 07 mov (%r15),%eax
* 2a: 3d 00 00 00 40 cmp $0x40000000,%eax <-- trapping instruction
2f: 7d 07 jge 0x38
31: 5b pop %rbx
32: 41 5e pop %r14
34: 41 5f pop %r15
36: 5d pop %rbp
37: c3 retq
38: 0f 0b ud2
3a: eb f5 jmp 0x31
3c: 44 89 f9 mov %r15d,%ecx
3f: 80 .byte 0x80