================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 Read of size 1 at addr ffff888054470418 by task udevd/5992 CPU: 3 UID: 0 PID: 5992 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:573 kasan_check_byte include/linux/kasan.h:401 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0xfc/0x330 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 p9_tag_remove net/9p/client.c:274 [inline] p9_req_put net/9p/client.c:282 [inline] p9_req_put+0xaf/0x250 net/9p/client.c:279 req_done+0x1dc/0x2e0 net/9p/trans_virtio.c:147 vring_interrupt+0x2cf/0x440 drivers/virtio/virtio_ring.c:2718 __handle_irq_event_percpu+0x236/0x890 kernel/irq/handle.c:211 handle_irq_event_percpu kernel/irq/handle.c:248 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:265 handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:172 [inline] handle_irq arch/x86/kernel/irq.c:255 [inline] call_irq_handler arch/x86/kernel/irq.c:311 [inline] __common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:326 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:319 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:preempt_schedule_irq+0x4c/0x90 kernel/sched/core.c:7190 Code: df 55 65 48 8b 2d 0c 6a 39 08 53 48 89 eb 48 c1 eb 03 48 01 c3 bf 01 00 00 00 e8 8f 72 11 f6 e8 ba c2 4d f6 fb bf 01 00 00 00 3f 96 ff ff 9c 58 fa f6 c4 02 75 1e bf 01 00 00 00 e8 3d 04 11 RSP: 0018:ffffc90003537788 EFLAGS: 00000202 RAX: 0000000000002057 RBX: ffffed1005e7a000 RCX: ffffffff81c707ef RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: 0000000000000001 RBP: ffff88802f3d0000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9088b4d7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872 Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 72 b9 ee 0e 0f 82 74 02 00 00 8b 35 0a ea ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 89 b4 18 12 0f 85 ad 02 00 00 48 83 c4 RSP: 0018:ffffc90003537890 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 0000000068c1bacb RDX: 0000000000000000 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400 RBP: 0000000000000002 R08: 00000000ffffffff R09: 00000000ffffffff R10: 0000000000000002 R11: ffff88802f3d0b30 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556 __call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3119 slab_free_hook mm/slub.c:2504 [inline] slab_free mm/slub.c:6670 [inline] kmem_cache_free+0x171/0x770 mm/slub.c:6781 file_free fs/file_table.c:79 [inline] __fput+0x68d/0xb70 fs/file_table.c:481 fput_close_sync+0x118/0x260 fs/file_table.c:573 __do_sys_close fs/open.c:1573 [inline] __se_sys_close fs/open.c:1558 [inline] __x64_sys_close+0x8b/0x120 fs/open.c:1558 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd631f15a67 Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffe53b62868 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 000055da07ca81e0 RCX: 00007fd631f15a67 RDX: 00007fd631fefea0 RSI: 000055da07cb62b0 RDI: 0000000000000008 RBP: 00007fd631fefff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544 Allocated by task 6306: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kmalloc_noprof include/linux/slab.h:957 [inline] p9_client_create+0xae/0xe40 net/9p/client.c:862 v9fs_session_init+0x40/0xd40 fs/9p/v9fs.c:442 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97 vfs_get_tree+0x8e/0x330 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7bf/0x23a0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6306: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6878 p9_client_create+0x6c5/0xe40 net/9p/client.c:941 v9fs_session_init+0x40/0xd40 fs/9p/v9fs.c:442 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97 vfs_get_tree+0x8e/0x330 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7bf/0x23a0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888054470400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888054470400, ffff888054470600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54470 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b442c80 ffffea000151ec00 dead000000000003 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442c80 ffffea000151ec00 dead000000000003 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001511c01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 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 5989, tgid 5989 (syz-executor), ts 374421399515, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x4fc/0x910 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0xaa0 net/ipv6/route.c:3809 addrconf_f6i_alloc+0x2da/0x660 net/ipv6/route.c:4678 ipv6_add_addr+0x531/0x2010 net/ipv6/addrconf.c:1126 inet6_addr_add+0x256/0x9b0 net/ipv6/addrconf.c:3050 inet6_rtm_newaddr+0x1619/0x1c50 net/ipv6/addrconf.c:5059 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550 page_owner free stack trace missing Memory state around the buggy address: ffff888054470300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888054470380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888054470400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888054470480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888054470500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: df 55 65 fists 0x65(%rbp) 3: 48 8b 2d 0c 6a 39 08 mov 0x8396a0c(%rip),%rbp # 0x8396a16 a: 53 push %rbx b: 48 89 eb mov %rbp,%rbx e: 48 c1 eb 03 shr $0x3,%rbx 12: 48 01 c3 add %rax,%rbx 15: bf 01 00 00 00 mov $0x1,%edi 1a: e8 8f 72 11 f6 call 0xf61172ae 1f: e8 ba c2 4d f6 call 0xf64dc2de 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 3f 96 ff ff call 0xffff966e <-- trapping instruction 2f: 9c pushf 30: 58 pop %rax 31: fa cli 32: f6 c4 02 test $0x2,%ah 35: 75 1e jne 0x55 37: bf 01 00 00 00 mov $0x1,%edi 3c: e8 .byte 0xe8 3d: 3d .byte 0x3d 3e: 04 11 add $0x11,%al