================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x4208/0x5de0 kernel/locking/lockdep.c:5004 Read of size 8 at addr ffff888070600c18 by task syz-executor.3/7235 CPU: 1 PID: 7235 Comm: syz-executor.3 Not tainted 6.6.0-rc3-syzkaller-00146-g9f3ebbef746f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 __lock_acquire+0x4208/0x5de0 kernel/locking/lockdep.c:5004 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 p9_tag_remove net/9p/client.c:394 [inline] p9_req_put net/9p/client.c:402 [inline] p9_req_put+0xc6/0x250 net/9p/client.c:399 req_done+0x1e7/0x2e0 net/9p/trans_virtio.c:147 vring_interrupt drivers/virtio/virtio_ring.c:2595 [inline] vring_interrupt+0x317/0x3f0 drivers/virtio/virtio_ring.c:2570 __handle_irq_event_percpu+0x22a/0x740 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x261/0xcf0 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0xdb/0x240 arch/x86/kernel/irq.c:257 common_interrupt+0x51/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 RIP: 0023:0xf721f86c Code: 24 14 8d 74 26 00 8b 45 08 8b 4d 0c 83 c5 08 89 ce 39 d0 19 fe 72 ef 89 44 24 0c 8b 44 24 10 89 4c 24 10 8b 74 24 14 83 e8 08 <89> f9 39 f2 19 d9 73 15 8d 74 26 00 8b 70 f8 8b 58 fc 83 e8 08 89 RSP: 002b:00000000ff9f7ab0 EFLAGS: 00000296 RAX: 00000000f6d71588 RBX: 00000000ffffffff RCX: 00000000ffffffff RDX: 00000000813a53d5 RSI: 00000000813a539e RDI: 00000000ffffffff RBP: 00000000f6d67c90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7238: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] p9_client_create+0xcf/0x1210 net/9p/client.c:978 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xcd0 fs/9p/vfs_super.c:123 legacy_get_tree+0x109/0x220 fs/fs_context.c:638 vfs_get_tree+0x8c/0x370 fs/super.c:1750 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __ia32_sys_mount+0x291/0x310 fs/namespace.c:3861 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 7238: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 p9_client_create+0xa14/0x1210 net/9p/client.c:1049 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xcd0 fs/9p/vfs_super.c:123 legacy_get_tree+0x109/0x220 fs/fs_context.c:638 vfs_get_tree+0x8c/0x370 fs/super.c:1750 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __ia32_sys_mount+0x291/0x310 fs/namespace.c:3861 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 insert_work+0x38/0x230 kernel/workqueue.c:1647 __queue_work+0x5d0/0x1050 kernel/workqueue.c:1799 call_timer_fn+0x19e/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1746 [inline] __run_timers+0x585/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 Second to last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372 drop_sysctl_table+0x1d4/0x3b0 fs/proc/proc_sysctl.c:1508 unregister_sysctl_table fs/proc/proc_sysctl.c:1529 [inline] unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1521 neigh_sysctl_unregister+0x5f/0x80 net/core/neighbour.c:3868 addrconf_ifdown.isra.0+0x162f/0x1c50 net/ipv6/addrconf.c:3945 addrconf_notify+0x22d/0x1920 net/ipv6/addrconf.c:3715 notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1970 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers net/core/dev.c:2022 [inline] unregister_netdevice_many_notify+0x85f/0x1a20 net/core/dev.c:10938 unregister_netdevice_many net/core/dev.c:10994 [inline] default_device_exit_batch+0x584/0x740 net/core/dev.c:11453 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175 cleanup_net+0x505/0xb20 net/core/net_namespace.c:614 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 The buggy address belongs to the object at ffff888070600c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888070600c00, ffff888070600e00) The buggy address belongs to the physical page: page:ffffea0001c18000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x70600 head:ffffea0001c18000 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000840(slab|head|node=1|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 04fff00000000840 ffff888012c42c80 ffffea00010c5b00 dead000000000002 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5208, tgid 5208 (syz-executor.1), ts 146818676028, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] inetdev_init+0x66/0x570 net/ipv4/devinet.c:269 inetdev_event+0x1156/0x1900 net/ipv4/devinet.c:1555 notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1970 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers net/core/dev.c:2022 [inline] register_netdevice+0xf84/0x1490 net/core/dev.c:10169 veth_newlink+0x4f6/0xa10 drivers/net/veth.c:1939 rtnl_newlink_create net/core/rtnetlink.c:3485 [inline] __rtnl_newlink+0x1177/0x1940 net/core/rtnetlink.c:3705 page_owner free stack trace missing Memory state around the buggy address: ffff888070600b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888070600b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888070600c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888070600c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888070600d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 24 14 and $0x14,%al 2: 8d 74 26 00 lea 0x0(%rsi,%riz,1),%esi 6: 8b 45 08 mov 0x8(%rbp),%eax 9: 8b 4d 0c mov 0xc(%rbp),%ecx c: 83 c5 08 add $0x8,%ebp f: 89 ce mov %ecx,%esi 11: 39 d0 cmp %edx,%eax 13: 19 fe sbb %edi,%esi 15: 72 ef jb 0x6 17: 89 44 24 0c mov %eax,0xc(%rsp) 1b: 8b 44 24 10 mov 0x10(%rsp),%eax 1f: 89 4c 24 10 mov %ecx,0x10(%rsp) 23: 8b 74 24 14 mov 0x14(%rsp),%esi 27: 83 e8 08 sub $0x8,%eax * 2a: 89 f9 mov %edi,%ecx <-- trapping instruction 2c: 39 f2 cmp %esi,%edx 2e: 19 d9 sbb %ebx,%ecx 30: 73 15 jae 0x47 32: 8d 74 26 00 lea 0x0(%rsi,%riz,1),%esi 36: 8b 70 f8 mov -0x8(%rax),%esi 39: 8b 58 fc mov -0x4(%rax),%ebx 3c: 83 e8 08 sub $0x8,%eax 3f: 89 .byte 0x89