================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [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 ffff888056df4018 by task syz-executor/5930 CPU: 3 UID: 0 PID: 5930 Comm: syz-executor 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 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0x148/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [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+0x2ef/0x650 drivers/virtio/virtio_ring.c:3254 __handle_irq_event_percpu+0x232/0x8e0 kernel/irq/handle.c:209 handle_irq_event_percpu kernel/irq/handle.c:246 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:263 handle_edge_irq+0x375/0x970 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:186 [inline] handle_irq arch/x86/kernel/irq.c:262 [inline] call_irq_handler arch/x86/kernel/irq.c:318 [inline] __common_interrupt+0xd8/0x2f0 arch/x86/kernel/irq.c:333 common_interrupt+0x60/0xe0 arch/x86/kernel/irq.c:326 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:handle_softirqs+0x1af/0x9e0 kernel/softirq.c:608 Code: 89 64 24 18 44 88 6c 24 1e 48 c7 c7 60 72 ad 8b e8 76 ef c6 09 31 d2 65 66 89 15 94 ca 44 12 e8 e7 a6 47 00 fb bb ff ff ff ff <49> c7 c6 c0 c0 40 8e 41 0f bc df 83 c3 01 0f 85 a3 00 00 00 e9 48 RSP: 0018:ffffc900006f8f30 EFLAGS: 00000202 RAX: 000000000016ec4a RBX: 00000000ffffffff RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8de72f1c RDI: ffffffff8c1af5a0 RBP: 00000000ffffc296 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 000000000000000a R13: 0000000000000000 R14: 0000000000400140 R15: 0000000000000200 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [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 16 1d 52 f6 48 89 df e8 fe 6c 52 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 65 a3 42 f6 65 8b 05 9e 0e 7b 08 85 c0 74 16 5b RSP: 0018:ffffc90003d4fbb0 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff888023960a38 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8de72f1c RDI: ffffffff8c1af5a0 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 1ffff920007a9f7f R13: ffff888023960a38 R14: ffff8880239602a8 R15: ffff88806a63bf80 task_rq_unlock kernel/sched/sched.h:1914 [inline] wake_up_new_task+0x8a5/0xe10 kernel/sched/core.c:4795 kernel_clone+0x21e/0x9a0 kernel/fork.c:2685 __do_sys_clone+0xd9/0x120 kernel/fork.c:2795 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa0b33c5212 Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd04d15880 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd04d15880 RCX: 00007fa0b33c5212 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd04d15a0c R08: 0000000000000000 R09: 0000000000000001 R10: 000055555d4897d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000023328 R15: 00007ffd04d15a60 Allocated by task 10162: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:950 [inline] p9_client_create+0xaf/0xd40 net/9p/client.c:862 v9fs_session_init+0x40/0xce0 fs/9p/v9fs.c:442 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount fs/namespace.c:3839 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4159 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount fs/namespace.c:4338 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10162: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2692 [inline] slab_free mm/slub.c:6143 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6461 p9_client_create+0x72d/0xd40 net/9p/client.c:941 v9fs_session_init+0x40/0xce0 fs/9p/v9fs.c:442 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount fs/namespace.c:3839 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4159 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount fs/namespace.c:4338 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888056df4000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888056df4000, ffff888056df4200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x56df4 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00015b7d01 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 110, tgid 110 (kworker/u32:5), ts 85099112417, free_ts 84985105964 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3269 [inline] allocate_slab mm/slub.c:3458 [inline] new_slab+0xa6/0x6d0 mm/slub.c:3516 refill_objects+0x26b/0x400 mm/slub.c:7153 refill_sheaf mm/slub.c:2818 [inline] alloc_full_sheaf mm/slub.c:2839 [inline] __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4602 alloc_from_pcs mm/slub.c:4695 [inline] slab_alloc_node mm/slub.c:4829 [inline] __do_kmalloc_node mm/slub.c:5237 [inline] __kmalloc_noprof+0x688/0x850 mm/slub.c:5250 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0xad0 net/ipv6/route.c:3819 ip6_route_add+0x4b/0x1d0 net/ipv6/route.c:3948 addrconf_add_mroute+0x1de/0x350 net/ipv6/addrconf.c:2551 addrconf_add_dev+0x14e/0x1a0 net/ipv6/addrconf.c:2569 addrconf_dev_config net/ipv6/addrconf.c:3483 [inline] addrconf_init_auto_addrs+0x10e/0x780 net/ipv6/addrconf.c:3571 addrconf_notify+0x9aa/0x19c0 net/ipv6/addrconf.c:3744 notifier_call_chain+0x99/0x420 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249 page last free pid 24 tgid 24 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 kasan_depopulate_vmalloc_pte+0x5d/0x80 mm/kasan/shadow.c:484 apply_to_pte_range mm/memory.c:3243 [inline] apply_to_pmd_range mm/memory.c:3287 [inline] apply_to_pud_range mm/memory.c:3323 [inline] apply_to_p4d_range mm/memory.c:3359 [inline] __apply_to_page_range+0xb1d/0x1520 mm/memory.c:3395 __kasan_release_vmalloc+0xd7/0xe0 mm/kasan/shadow.c:602 kasan_release_vmalloc include/linux/kasan.h:593 [inline] kasan_release_vmalloc_node mm/vmalloc.c:2290 [inline] purge_vmap_node+0x210/0xb40 mm/vmalloc.c:2312 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888056df3f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888056df3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888056df4000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888056df4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888056df4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 89 64 24 18 mov %esp,0x18(%rsp) 4: 44 88 6c 24 1e mov %r13b,0x1e(%rsp) 9: 48 c7 c7 60 72 ad 8b mov $0xffffffff8bad7260,%rdi 10: e8 76 ef c6 09 call 0x9c6ef8b 15: 31 d2 xor %edx,%edx 17: 65 66 89 15 94 ca 44 mov %dx,%gs:0x1244ca94(%rip) # 0x1244cab3 1e: 12 1f: e8 e7 a6 47 00 call 0x47a70b 24: fb sti 25: bb ff ff ff ff mov $0xffffffff,%ebx * 2a: 49 c7 c6 c0 c0 40 8e mov $0xffffffff8e40c0c0,%r14 <-- trapping instruction 31: 41 0f bc df bsf %r15d,%ebx 35: 83 c3 01 add $0x1,%ebx 38: 0f 85 a3 00 00 00 jne 0xe1 3e: e9 .byte 0xe9 3f: 48 rex.W