================================================================== 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 ffff88805def0418 by task migration/0/19 CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Stopper: migration_cpu_stop+0x0/0xdc0 kernel/sched/core.c:3250 <- affine_move_task+0xb61/0x10c0 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:580 kasan_check_byte include/linux/kasan.h:401 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0xfc/0x350 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:397 [inline] p9_req_put net/9p/client.c:405 [inline] p9_req_put+0xaf/0x250 net/9p/client.c:402 req_done+0x1dc/0x2e0 net/9p/trans_virtio.c:147 vring_interrupt drivers/virtio/virtio_ring.c:2718 [inline] vring_interrupt+0x31e/0x400 drivers/virtio/virtio_ring.c:2693 __handle_irq_event_percpu+0x236/0x920 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257 handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:310 [inline] __common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:325 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 a6 41 38 f6 48 89 df e8 8e 95 38 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 b5 9d 28 f6 65 8b 05 7e 15 41 08 85 c0 74 16 5b RSP: 0018:ffffc9000045fcc8 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffffc90006f27b28 RCX: ffffffff81c4682f RDX: 0000000000000000 RSI: ffffffff8da28350 RDI: ffffffff8bf075c0 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff908242d7 R11: 0000000000000001 R12: 0000000000000001 R13: ffffc90006f27b18 R14: 1ffff9200008bfa3 R15: ffff88802b33a4c0 migration_cpu_stop+0x6bc/0xdc0 kernel/sched/core.c:2628 cpu_stopper_thread+0x21e/0x490 kernel/stop_machine.c:512 smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 25733: 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:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] p9_client_create+0xc7/0x11d0 net/9p/client.c:985 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122 legacy_get_tree+0x10c/0x220 fs/fs_context.c:663 vfs_get_tree+0x8e/0x340 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount fs/namespace.c:3727 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4037 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount fs/namespace.c:4215 [inline] __ia32_sys_mount+0x291/0x310 fs/namespace.c:4215 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 25733: 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:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] 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:2539 [inline] slab_free mm/slub.c:6634 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6841 p9_client_create+0xa28/0x11d0 net/9p/client.c:1064 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122 legacy_get_tree+0x10c/0x220 fs/fs_context.c:663 vfs_get_tree+0x8e/0x340 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount fs/namespace.c:3727 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4037 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount fs/namespace.c:4215 [inline] __ia32_sys_mount+0x291/0x310 fs/namespace.c:4215 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff88805def0400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff88805def0400, ffff88805def0600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5def0 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801b442c80 ffffea0001504400 dead000000000002 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff88801b442c80 ffffea0001504400 dead000000000002 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 04fff00000000002 ffffea000177bc01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5952, tgid 5952 (syz-executor), ts 55921710512, free_ts 53520810765 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3055 [inline] allocate_slab mm/slub.c:3228 [inline] new_slab+0x24a/0x360 mm/slub.c:3282 ___slab_alloc+0xd79/0x1a50 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5272 [inline] __do_kmalloc_node mm/slub.c:5645 [inline] __kmalloc_noprof+0x501/0x880 mm/slub.c:5658 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/0x870 net/ipv6/route.c:3809 ip6_route_add.part.0+0x22/0x1d0 net/ipv6/route.c:3938 ip6_route_add+0x45/0x60 net/ipv6/route.c:3935 addrconf_prefix_route+0x2fd/0x510 net/ipv6/addrconf.c:2488 fixup_permanent_addr net/ipv6/addrconf.c:3598 [inline] addrconf_permanent_addr net/ipv6/addrconf.c:3622 [inline] addrconf_notify+0x12c6/0x19e0 net/ipv6/addrconf.c:3694 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229 page last free pid 5952 tgid 5952 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906 discard_slab mm/slub.c:3326 [inline] __put_partials+0x130/0x170 mm/slub.c:3872 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4974 [inline] slab_alloc_node mm/slub.c:5284 [inline] __kmalloc_cache_noprof+0x274/0x780 mm/slub.c:5762 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ref_tracker_alloc+0x18e/0x5b0 lib/ref_tracker.c:271 __netdev_tracker_alloc include/linux/netdevice.h:4375 [inline] netdev_hold include/linux/netdevice.h:4404 [inline] netdev_hold include/linux/netdevice.h:4399 [inline] rx_queue_add_kobject net/core/net-sysfs.c:1257 [inline] net_rx_queue_update_kobjects+0x334/0x770 net/core/net-sysfs.c:1322 register_queue_kobjects net/core/net-sysfs.c:2114 [inline] netdev_register_kobject+0x290/0x3d0 net/core/net-sysfs.c:2362 register_netdevice+0x13dc/0x2270 net/core/dev.c:11294 bond_newlink+0x6a/0x100 drivers/net/bonding/bond_netlink.c:601 rtnl_newlink_create net/core/rtnetlink.c:3833 [inline] __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0xc45/0x2000 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6951 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 Memory state around the buggy address: ffff88805def0300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805def0380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805def0400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805def0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805def0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: f5 cmc 1: 53 push %rbx 2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi 7: 48 89 fb mov %rdi,%rbx a: 48 83 c7 18 add $0x18,%rdi e: e8 a6 41 38 f6 call 0xf63841b9 13: 48 89 df mov %rbx,%rdi 16: e8 8e 95 38 f6 call 0xf63895a9 1b: f7 c5 00 02 00 00 test $0x200,%ebp 21: 75 23 jne 0x46 23: 9c pushf 24: 58 pop %rax 25: f6 c4 02 test $0x2,%ah 28: 75 37 jne 0x61 * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 b5 9d 28 f6 call 0xf6289de9 34: 65 8b 05 7e 15 41 08 mov %gs:0x841157e(%rip),%eax # 0x84115b9 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx