================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 Read of size 8 at addr ffff88807082a380 by task kworker/u4:6/4040 CPU: 1 PID: 4040 Comm: kworker/u4:6 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_is_held_type+0xff/0x140 kernel/locking/lockdep.c:5689 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 c4 25 a4 76 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb b9 0f 0b 48 RSP: 0018:ffffc900034174d8 EFLAGS: 00000286 RAX: 0000000000000046 RBX: 0000000000000008 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8bd7f140 R08: 0000000000000000 R09: ffff88807d0e00ef R10: ffffed100fa1c01d R11: 0000000000000001 R12: ffff8880167a6280 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff8880167a6df8 lock_is_held include/linux/lockdep.h:283 [inline] __might_resched+0x21/0x2c0 kernel/sched/core.c:9701 kernfs_drain fs/kernfs/dir.c:476 [inline] __kernfs_remove+0x491/0xb20 fs/kernfs/dir.c:1376 kernfs_remove_by_name_ns+0xa8/0x110 fs/kernfs/dir.c:1574 kernfs_remove_by_name include/linux/kernfs.h:558 [inline] remove_files+0x96/0x1c0 fs/sysfs/group.c:28 sysfs_remove_group+0x87/0x170 fs/sysfs/group.c:288 sysfs_remove_groups fs/sysfs/group.c:312 [inline] sysfs_remove_groups+0x5c/0xa0 fs/sysfs/group.c:304 device_remove_groups drivers/base/core.c:2478 [inline] device_remove_attrs+0x134/0x170 drivers/base/core.c:2684 device_del+0x4eb/0xc80 drivers/base/core.c:3591 unregister_netdevice_many+0xd22/0x1890 net/core/dev.c:10778 unregister_netdevice_queue net/core/dev.c:10683 [inline] unregister_netdevice_queue+0x2dd/0x3c0 net/core/dev.c:10673 unregister_netdevice include/linux/netdevice.h:2954 [inline] nsim_destroy+0x3f/0x190 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x191/0x250 drivers/net/netdevsim/dev.c:1427 nsim_dev_port_del_all+0x85/0xe0 drivers/net/netdevsim/dev.c:1440 nsim_dev_reload_destroy+0x11f/0x420 drivers/net/netdevsim/dev.c:1659 nsim_dev_reload_down+0xdf/0x180 drivers/net/netdevsim/dev.c:962 devlink_reload+0x1c2/0x6b0 net/core/devlink.c:4070 devlink_pernet_pre_exit+0x17e/0x220 net/core/devlink.c:11476 ops_pre_exit_list net/core/net_namespace.c:152 [inline] cleanup_net+0x451/0xb00 net/core/net_namespace.c:582 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 3890: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x85/0xb0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc mm/slab.c:3316 [inline] __kmem_cache_alloc_lru mm/slab.c:3493 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3513 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3132 __do_sys_unshare kernel/fork.c:3203 [inline] __se_sys_unshare kernel/fork.c:3201 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 4040: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x13d/0x180 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3439 [inline] kmem_cache_free.part.0+0xa9/0x240 mm/slab.c:3749 net_free net/core/net_namespace.c:432 [inline] net_free net/core/net_namespace.c:428 [inline] cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:615 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x62e/0x1140 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x62e/0x1140 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 The buggy address belongs to the object at ffff88807082a0c0 which belongs to the cache net_namespace of size 6784 The buggy address is located 704 bytes inside of 6784-byte region [ffff88807082a0c0, ffff88807082bb40) The buggy address belongs to the physical page: page:ffffea0001c20a80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7082a head:ffffea0001c20a80 order:1 compound_mapcount:0 compound_pincount:0 memcg:ffff88801b9af541 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001d17008 ffffea0001f99d88 ffff8880114d3600 raw: 0000000000000000 ffff88807082a0c0 0000000100000001 ffff88801b9af541 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 3890, tgid 3890 (syz-executor.5), ts 67607864893, free_ts 67594728863 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 __alloc_pages_node include/linux/gfp.h:587 [inline] kmem_getpages mm/slab.c:1378 [inline] cache_grow_begin+0x75/0x350 mm/slab.c:2584 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957 ____cache_alloc mm/slab.c:3040 [inline] ____cache_alloc mm/slab.c:3023 [inline] __do_cache_alloc mm/slab.c:3267 [inline] slab_alloc mm/slab.c:3309 [inline] __kmem_cache_alloc_lru mm/slab.c:3493 [inline] kmem_cache_alloc+0x450/0x560 mm/slab.c:3513 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3132 __do_sys_unshare kernel/fork.c:3203 [inline] __se_sys_unshare kernel/fork.c:3201 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 slab_destroy mm/slab.c:1630 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1650 cache_flusharray mm/slab.c:3411 [inline] ___cache_free+0x34e/0x670 mm/slab.c:3474 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc_node mm/slab.c:3253 [inline] kmem_cache_alloc_node+0x2ea/0x590 mm/slab.c:3607 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1300 [inline] alloc_skb_with_frags+0x93/0x730 net/core/skbuff.c:5995 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2600 unix_dgram_sendmsg+0x414/0x1a90 net/unix/af_unix.c:1896 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_write_iter+0x283/0x3c0 net/socket.c:1061 call_write_iter include/linux/fs.h:2050 [inline] new_sync_write+0x38a/0x560 fs/read_write.c:504 vfs_write+0x7c0/0xac0 fs/read_write.c:591 Memory state around the buggy address: ffff88807082a280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807082a300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807082a380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807082a400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807082a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: b8 ff ff ff ff mov $0xffffffff,%eax 7: 65 0f c1 05 c4 25 a4 xadd %eax,%gs:0x76a425c4(%rip) # 0x76a425d3 e: 76 f: 83 f8 01 cmp $0x1,%eax 12: 75 29 jne 0x3d 14: 9c pushfq 15: 58 pop %rax 16: f6 c4 02 test $0x2,%ah 19: 75 3d jne 0x58 1b: 48 f7 04 24 00 02 00 testq $0x200,(%rsp) 22: 00 23: 74 01 je 0x26 25: fb sti 26: 48 83 c4 08 add $0x8,%rsp * 2a: 44 89 e8 mov %r13d,%eax <-- trapping instruction 2d: 5b pop %rbx 2e: 5d pop %rbp 2f: 41 5c pop %r12 31: 41 5d pop %r13 33: 41 5e pop %r14 35: 41 5f pop %r15 37: c3 retq 38: 45 31 ed xor %r13d,%r13d 3b: eb b9 jmp 0xfffffff6 3d: 0f 0b ud2 3f: 48 rex.W