================================================================== 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 ffff88802ad85418 by task swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/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 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:568 kasan_check_byte include/linux/kasan.h:399 [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:2719 [inline] vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2694 __handle_irq_event_percpu+0x22c/0x7d0 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+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+0x61/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x1fc/0x2f0 kernel/locking/lockdep.c:5879 Code: 85 c0 74 0f 48 8b 78 08 4c 89 e2 48 89 de e8 0b d7 fe ff 65 ff 0d 84 74 3e 12 0f 85 39 fe ff ff e8 a9 01 95 ff e9 2f fe ff ff 6f ee 08 00 84 c0 0f 85 42 fe ff ff 80 3d cb 77 fc 0e 00 0f 85 RSP: 0000:ffffc90000007940 EFLAGS: 00000297 RAX: 0000000000000000 RBX: ffffffff8e5c10a0 RCX: ffffc90000008001 RDX: 0000000000000000 RSI: ffffffff816ab8a4 RDI: ffffffff8e5c10a0 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000012034 R12: ffffffff816ab8a4 R13: ffffc900000079f8 R14: ffffc90000007d48 R15: ffffc90000007a2c rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4782 put_pid.part.0+0xe9/0x130 kernel/pid.c:104 put_pid kernel/pid.c:98 [inline] delayed_put_pid+0x23/0x30 kernel/pid.c:113 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x799/0x1530 kernel/rcu/tree.c:2861 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5225 Code: fb 09 00 00 44 8b 05 49 11 23 0f 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 9f 4a 3a 00 fb 65 48 8b 1d 0e 2c 4d 12 <48> 8d bb 18 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0000:ffffffff8e207be8 EFLAGS: 00000202 RAX: 00000000000ba249 RBX: ffffffff8e2977c0 RCX: ffffffff81c2ed9f RDX: 0000000000000000 RSI: ffffffff8de4cbd1 RDI: ffffffff8c162d00 RBP: ffffffff8e207c30 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90ab8397 R11: 0000000000000000 R12: ffff88802b23a440 R13: ffff888024220000 R14: 0000000000000000 R15: dffffc0000000000 context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1198/0x5de0 kernel/sched/core.c:6961 schedule_idle+0x5c/0x90 kernel/sched/core.c:7084 do_idle+0x2b6/0x510 kernel/sched/idle.c:358 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148 Allocated by task 6105: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] p9_client_create+0xc7/0x11c0 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+0x109/0x220 fs/fs_context.c:666 vfs_get_tree+0x8b/0x340 fs/super.c:1815 do_new_mount fs/namespace.c:3808 [inline] path_mount+0x1513/0x2000 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount fs/namespace.c:4324 [inline] __ia32_sys_mount+0x28b/0x310 fs/namespace.c:4324 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 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 6105: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4879 p9_client_create+0xa28/0x11c0 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+0x109/0x220 fs/fs_context.c:666 vfs_get_tree+0x8b/0x340 fs/super.c:1815 do_new_mount fs/namespace.c:3808 [inline] path_mount+0x1513/0x2000 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount fs/namespace.c:4324 [inline] __ia32_sys_mount+0x28b/0x310 fs/namespace.c:4324 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 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 ffff88802ad85400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff88802ad85400, ffff88802ad85600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ad84 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 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842c80 dead000000000122 0000000000000000 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000ab6101 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 5980, tgid 5980 (syz-executor), ts 58681152306, free_ts 58655406162 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_pages_slowpath mm/page_alloc.c:4679 [inline] __alloc_frozen_pages_noprof+0x58b/0x23f0 mm/page_alloc.c:5161 alloc_slab_page mm/slub.c:2489 [inline] allocate_slab mm/slub.c:2655 [inline] new_slab+0x94/0x330 mm/slub.c:2709 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981 __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_node_noprof+0x2ed/0x500 mm/slub.c:4371 kmalloc_array_node_noprof include/linux/slab.h:1020 [inline] alloc_slab_obj_exts+0x41/0xa0 mm/slub.c:2028 __memcg_slab_post_alloc_hook+0x255/0x960 mm/memcontrol.c:3174 memcg_slab_post_alloc_hook mm/slub.c:2216 [inline] slab_post_alloc_hook mm/slub.c:4190 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x307/0x3b0 mm/slub.c:4236 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_clone+0xd8/0x5c0 mm/rmap.c:288 anon_vma_fork+0x7a/0x620 mm/rmap.c:351 dup_mmap+0x152e/0x21d0 mm/mmap.c:1797 dup_mm kernel/fork.c:1485 [inline] copy_mm kernel/fork.c:1537 [inline] copy_process+0x4081/0x7690 kernel/fork.c:2175 kernel_clone+0xfc/0x930 kernel/fork.c:2605 __do_compat_sys_ia32_clone+0xcb/0x110 arch/x86/kernel/sys_ia32.c:254 page last free pid 5980 tgid 5980 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 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:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_lru_noprof+0x1d0/0x3b0 mm/slub.c:4248 shmem_alloc_inode+0x25/0x50 mm/shmem.c:5211 alloc_inode+0x64/0x240 fs/inode.c:346 new_inode+0x22/0x1c0 fs/inode.c:1145 __shmem_get_inode mm/shmem.c:3110 [inline] shmem_get_inode+0x19a/0xfb0 mm/shmem.c:3184 shmem_mknod+0x1a8/0x450 mm/shmem.c:3905 shmem_mkdir+0x31/0x80 mm/shmem.c:3971 vfs_mkdir+0x590/0x8c0 fs/namei.c:4366 do_mkdirat+0x304/0x3e0 fs/namei.c:4399 __do_sys_mkdirat fs/namei.c:4416 [inline] __se_sys_mkdirat fs/namei.c:4414 [inline] __ia32_sys_mkdirat+0x82/0xb0 fs/namei.c:4414 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 Memory state around the buggy address: ffff88802ad85300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802ad85380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802ad85400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802ad85480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802ad85500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 85 c0 test %eax,%eax 2: 74 0f je 0x13 4: 48 8b 78 08 mov 0x8(%rax),%rdi 8: 4c 89 e2 mov %r12,%rdx b: 48 89 de mov %rbx,%rsi e: e8 0b d7 fe ff call 0xfffed71e 13: 65 ff 0d 84 74 3e 12 decl %gs:0x123e7484(%rip) # 0x123e749e 1a: 0f 85 39 fe ff ff jne 0xfffffe59 20: e8 a9 01 95 ff call 0xff9501ce 25: e9 2f fe ff ff jmp 0xfffffe59 * 2a: e8 6f ee 08 00 call 0x8ee9e <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 42 fe ff ff jne 0xfffffe79 37: 80 3d cb 77 fc 0e 00 cmpb $0x0,0xefc77cb(%rip) # 0xefc7809 3e: 0f .byte 0xf 3f: 85 .byte 0x85