================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 Read of size 1 at addr ffff88806149bfc5 by task syz-executor.0/24154 CPU: 0 PID: 24154 Comm: syz-executor.0 Not tainted 6.1.83-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:665 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:lock_is_held_type+0x137/0x180 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000502f8f8 EFLAGS: 00000206 RAX: 6bb98cb745d97700 RBX: 0000000000000001 RCX: ffff888048230000 RDX: 0000000000000000 RSI: ffffffff8aebffc0 RDI: ffffffff8b3d2b40 RBP: 0000000000000000 R08: ffffffff81f7125c R09: ffffed100ea71b32 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246 R13: ffff888048230000 R14: 00000000ffffffff R15: ffffffff8d12a9a0 lock_is_held include/linux/lockdep.h:283 [inline] __might_resched+0xa1/0x780 kernel/sched/core.c:9904 shrink_dcache_parent+0x177/0x4a0 fs/dcache.c:1633 d_invalidate+0x118/0x2d0 fs/dcache.c:1738 simple_recursive_removal+0x3a7/0x850 fs/libfs.c:291 debugfs_remove+0x45/0x60 fs/debugfs/inode.c:778 kvm_destroy_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:1035 [inline] kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1305 [inline] kvm_put_kvm+0x135/0x18a0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1370 kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3856 __fput+0x3b7/0x890 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5f3fa7cc9a Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24 RSP: 002b:00007fff46c9f370 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007f5f3fa7cc9a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007f5f3fbad980 R08: 0000001b30320000 R09: 0000000000001027 R10: 0000000081328f98 R11: 0000000000000293 R12: 00000000000c0799 R13: ffffffffffffffff R14: 00007f5f3f600000 R15: 00000000000c0458 Allocated by task 9380: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 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:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 18210: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x292/0x510 mm/slub.c:3683 net_free net/core/net_namespace.c:439 [inline] cleanup_net+0xab5/0xb60 net/core/net_namespace.c:622 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1790 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1790 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 The buggy address belongs to the object at ffff88806149b880 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff88806149b880, ffff88806149d3c0) The buggy address belongs to the physical page: page:ffffea0001852600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x61498 head:ffffea0001852600 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888063158641 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001d53c00 dead000000000002 ffff888140009500 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff888063158641 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5091, tgid 5090 (syz-executor.2), ts 170033952002, free_ts 136852870760 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5545 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x1a5/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 copy_namespaces+0x397/0x3f0 kernel/nsproxy.c:178 copy_process+0x1ab8/0x4060 kernel/fork.c:2270 kernel_clone+0x222/0x920 kernel/fork.c:2682 __do_sys_clone kernel/fork.c:2823 [inline] __se_sys_clone kernel/fork.c:2807 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2807 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1440 [inline] free_pcp_prepare mm/page_alloc.c:1490 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453 __vunmap+0x834/0x9a0 mm/vmalloc.c:2717 kcov_put kernel/kcov.c:428 [inline] kcov_close+0x27/0x50 kernel/kcov.c:524 __fput+0x3b7/0x890 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa73/0x26a0 kernel/exit.c:869 do_group_exit+0x202/0x2b0 kernel/exit.c:1019 __do_sys_exit_group kernel/exit.c:1030 [inline] __se_sys_exit_group kernel/exit.c:1028 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88806149be80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806149bf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806149bf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806149c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806149c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 75 40 jne 0x42 2: 48 c7 04 24 00 00 00 movq $0x0,(%rsp) 9: 00 a: 9c pushf b: 8f 04 24 pop (%rsp) e: f7 04 24 00 02 00 00 testl $0x200,(%rsp) 15: 75 46 jne 0x5d 17: 41 f7 c4 00 02 00 00 test $0x200,%r12d 1e: 74 01 je 0x21 20: fb sti 21: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax 28: 00 00 * 2a: 48 3b 44 24 08 cmp 0x8(%rsp),%rax <-- trapping instruction 2f: 75 3c jne 0x6d 31: 89 e8 mov %ebp,%eax 33: 48 83 c4 10 add $0x10,%rsp 37: 5b pop %rbx 38: 41 5c pop %r12 3a: 41 5d pop %r13 3c: 41 5e pop %r14 3e: 41 5f pop %r15