================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3ee7/0x56d0 kernel/locking/lockdep.c:4923 Read of size 8 at addr ffff88801aa1a018 by task udevd/3129 CPU: 1 PID: 3129 Comm: udevd Not tainted 6.0.0-rc3-syzkaller-00031-gc5e4d5e99162 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 __lock_acquire+0x3ee7/0x56d0 kernel/locking/lockdep.c:4923 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 p9_tag_remove net/9p/client.c:367 [inline] p9_req_put net/9p/client.c:375 [inline] p9_req_put+0xc6/0x250 net/9p/client.c:372 req_done+0x1de/0x2e0 net/9p/trans_virtio.c:148 vring_interrupt drivers/virtio/virtio_ring.c:2462 [inline] vring_interrupt+0x29d/0x3d0 drivers/virtio/virtio_ring.c:2437 __handle_irq_event_percpu+0x227/0x870 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xa7/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:819 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:231 [inline] __common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250 common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:640 RIP: 0010:path_init+0x78f/0x1910 fs/namei.c:2380 Code: ff 48 c7 c2 80 db fb 89 be c3 02 00 00 48 c7 c7 c0 da fb 89 c6 05 de 1b ef 0b 01 e8 2b 6d 60 07 e9 c5 f9 ff ff e8 61 bc a1 ff <49> 8d 44 24 20 48 89 c2 48 89 45 a8 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc90002a2fb48 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000040 RCX: 0000000000000000 RDX: ffff888015b43b00 RSI: ffffffff81da4dcf RDI: 0000000000000005 RBP: ffffc90002a2fbe0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90002a2fc88 R13: 0000000000000000 R14: ffffffff8bc14680 R15: 0000000000000000 path_lookupat+0x30/0x840 fs/namei.c:2464 filename_lookup+0x1ce/0x590 fs/namei.c:2503 user_path_at_empty+0x42/0x60 fs/namei.c:2876 do_readlinkat+0xcd/0x2f0 fs/stat.c:456 __do_sys_readlink fs/stat.c:489 [inline] __se_sys_readlink fs/stat.c:486 [inline] __x64_sys_readlink+0x74/0xb0 fs/stat.c:486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f3e07727277 Code: 73 01 c3 48 8b 0d 01 dc 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d d1 db 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc35017368 EFLAGS: 00000206 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffc35017fc8 RCX: 00007f3e07727277 RDX: 0000000000000400 RSI: 00007ffc35017778 RDI: 00007ffc35017378 RBP: 00007ffc35017bb8 R08: 00005634acb1d27d R09: 0000000000000000 R10: 0000000000000012 R11: 0000000000000206 R12: 0000000000000200 R13: 00007ffc35017778 R14: 00007ffc35017378 R15: 0000000000000000 Allocated by task 32436: 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:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc include/linux/slab.h:600 [inline] p9_client_create+0xaf/0x1070 net/9p/client.c:934 v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408 v9fs_mount+0xba/0xc90 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1530 do_new_mount fs/namespace.c:3040 [inline] path_mount+0x1326/0x1e20 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __ia32_sys_mount+0x27e/0x300 fs/namespace.c:3568 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 32436: 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:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kfree+0xe2/0x580 mm/slub.c:4562 p9_client_create+0x7a6/0x1070 net/9p/client.c:1005 v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408 v9fs_mount+0xba/0xc90 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1530 do_new_mount fs/namespace.c:3040 [inline] path_mount+0x1326/0x1e20 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __ia32_sys_mount+0x27e/0x300 fs/namespace.c:3568 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1210 kernel/workqueue.c:1517 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1210 kernel/workqueue.c:1517 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 The buggy address belongs to the object at ffff88801aa1a000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of 512-byte region [ffff88801aa1a000, ffff88801aa1a200) The buggy address belongs to the physical page: page:ffffea00006a8600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1aa18 head:ffffea00006a8600 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888011842c80 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 3716, tgid 3716 (syz-executor.3), ts 245258350978, free_ts 244829495510 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] __kmalloc_node_track_caller+0x2f2/0x380 mm/slub.c:4955 kmalloc_reserve net/core/skbuff.c:358 [inline] __alloc_skb+0xd9/0x2f0 net/core/skbuff.c:430 alloc_skb include/linux/skbuff.h:1257 [inline] alloc_uevent_skb+0x7b/0x210 lib/kobject_uevent.c:290 uevent_net_broadcast_tagged lib/kobject_uevent.c:351 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:412 [inline] kobject_uevent_env+0x110a/0x1640 lib/kobject_uevent.c:593 __kobject_del+0x160/0x1f0 lib/kobject.c:585 kobject_cleanup lib/kobject.c:664 [inline] kobject_release lib/kobject.c:704 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2ed/0x4c0 lib/kobject.c:721 net_rx_queue_update_kobjects+0x3f3/0x510 net/core/net-sysfs.c:1128 netif_set_real_num_rx_queues+0x161/0x200 net/core/dev.c:2941 veth_init_queues drivers/net/veth.c:1692 [inline] veth_init_queues+0x14d/0x190 drivers/net/veth.c:1682 veth_newlink+0x687/0x9a0 drivers/net/veth.c:1813 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] kmem_cache_alloc_trace+0x2c0/0x3e0 mm/slub.c:3282 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] kobject_uevent_env+0x230/0x1640 lib/kobject_uevent.c:524 __kobject_del+0x160/0x1f0 lib/kobject.c:585 kobject_cleanup lib/kobject.c:664 [inline] kobject_release lib/kobject.c:704 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2ed/0x4c0 lib/kobject.c:721 netdev_queue_update_kobjects+0x367/0x4e0 net/core/net-sysfs.c:1733 netif_set_real_num_tx_queues+0x1b6/0x770 net/core/dev.c:2893 veth_init_queues+0xdd/0x190 drivers/net/veth.c:1687 veth_newlink+0x687/0x9a0 drivers/net/veth.c:1813 rtnl_newlink_create net/core/rtnetlink.c:3363 [inline] __rtnl_newlink+0x1087/0x17e0 net/core/rtnetlink.c:3580 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090 Memory state around the buggy address: ffff88801aa19f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801aa19f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801aa1a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801aa1a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801aa1a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: ff 48 c7 decl -0x39(%rax) 3: c2 80 db retq $0xdb80 6: fb sti 7: 89 be c3 02 00 00 mov %edi,0x2c3(%rsi) d: 48 c7 c7 c0 da fb 89 mov $0xffffffff89fbdac0,%rdi 14: c6 05 de 1b ef 0b 01 movb $0x1,0xbef1bde(%rip) # 0xbef1bf9 1b: e8 2b 6d 60 07 callq 0x7606d4b 20: e9 c5 f9 ff ff jmpq 0xfffff9ea 25: e8 61 bc a1 ff callq 0xffa1bc8b * 2a: 49 8d 44 24 20 lea 0x20(%r12),%rax <-- trapping instruction 2f: 48 89 c2 mov %rax,%rdx 32: 48 89 45 a8 mov %rax,-0x58(%rbp) 36: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 3d: fc ff df