================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2d90/0x3c40 kernel/locking/lockdep.c:5091 Read of size 8 at addr ffff888021c37818 by task kworker/u32:7/1140 CPU: 0 UID: 0 PID: 1140 Comm: kworker/u32:7 Not tainted 6.13.0-syzkaller-08291-g805ba04cb7cc #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound toggle_allocation_gate 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+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 __lock_acquire+0x2d90/0x3c40 kernel/locking/lockdep.c:5091 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __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+0x1e7/0x2f0 net/9p/trans_virtio.c:147 vring_interrupt drivers/virtio/virtio_ring.c:2715 [inline] vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2690 __handle_irq_event_percpu+0x229/0x7d0 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+0x263/0xd10 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:247 [inline] call_irq_handler arch/x86/kernel/irq.c:259 [inline] __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:285 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:kvm_hypercall1 arch/x86/include/asm/kvm_para.h:59 [inline] RIP: 0010:kvm_smp_send_call_func_ipi+0x1e5/0x250 arch/x86/kernel/kvm.c:644 Code: 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 5d 8b 1b b8 0b 00 00 00 0f 01 c1 3a ff ff ff e8 81 b2 50 00 90 0f 0b 48 89 df e8 a6 91 b3 00 e9 RSP: 0018:ffffc90006b078f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff8168285f RDX: 0000000000000000 RSI: ffffffff8168286d RDI: ffffffff8da66cf8 RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: fffffbfff1c042ac R13: dffffc0000000000 R14: 0000000000000003 R15: 0000000000000003 arch_send_call_function_ipi_mask arch/x86/include/asm/smp.h:99 [inline] send_call_function_ipi_mask kernel/smp.c:127 [inline] smp_call_function_many_cond+0xc7b/0x12c0 kernel/smp.c:869 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x561/0x760 arch/x86/kernel/alternative.c:2407 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_flush arch/x86/kernel/alternative.c:2512 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:849 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:841 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 13438: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:901 [inline] p9_client_create+0xc8/0x11a0 net/9p/client.c:985 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1814 do_new_mount fs/namespace.c:3560 [inline] path_mount+0x6e1/0x1f00 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount fs/namespace.c:4088 [inline] __ia32_sys_mount+0x28d/0x310 fs/namespace.c:4088 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 13438: 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:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x2c4/0x4d0 mm/slub.c:4757 p9_client_create+0x97d/0x11a0 net/9p/client.c:1064 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1814 do_new_mount fs/namespace.c:3560 [inline] path_mount+0x6e1/0x1f00 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount fs/namespace.c:4088 [inline] __ia32_sys_mount+0x28d/0x310 fs/namespace.c:4088 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888021c37800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888021c37800, ffff888021c37a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21c34 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 ffff88801b042c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000870d01 ffffffffffffffff 0000000000000000 head: 0000000000000004 0000000000000000 00000000ffffffff 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 5659, tgid 5659 (dhcpcd), ts 380757740085, free_ts 375444261620 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_slab_page mm/slub.c:2425 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x94/0x330 mm/slub.c:2640 ___slab_alloc+0xbfa/0x1600 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_node_noprof+0x2f0/0x520 mm/slub.c:4300 kmalloc_array_node_noprof include/linux/slab.h:1018 [inline] alloc_slab_obj_exts+0x41/0xa0 mm/slub.c:1964 account_slab mm/slub.c:2550 [inline] allocate_slab mm/slub.c:2605 [inline] new_slab+0x285/0x330 mm/slub.c:2640 ___slab_alloc+0xbfa/0x1600 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] kmem_cache_alloc_noprof+0xeb/0x3b0 mm/slub.c:4171 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_fork+0x200/0x620 mm/rmap.c:364 dup_mmap kernel/fork.c:711 [inline] dup_mm kernel/fork.c:1689 [inline] copy_mm+0x1b10/0x2690 kernel/fork.c:1741 copy_process+0x3e6d/0x6f20 kernel/fork.c:2392 kernel_clone+0xfd/0x960 kernel/fork.c:2804 page last free pid 64 tgid 64 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 __folio_put+0x32a/0x450 mm/swap.c:112 kvfree+0x47/0x50 mm/util.c:705 io_ring_ctx_free io_uring/io_uring.c:2734 [inline] io_ring_exit_work+0xe96/0x1ba0 io_uring/io_uring.c:2937 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff888021c37700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888021c37780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888021c37800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021c37880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021c37900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 48 89 da mov %rbx,%rdx 3: 48 c1 ea 03 shr $0x3,%rdx 7: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx b: 48 89 d8 mov %rbx,%rax e: 83 e0 07 and $0x7,%eax 11: 83 c0 03 add $0x3,%eax 14: 38 d0 cmp %dl,%al 16: 7c 04 jl 0x1c 18: 84 d2 test %dl,%dl 1a: 75 5d jne 0x79 1c: 8b 1b mov (%rbx),%ebx 1e: b8 0b 00 00 00 mov $0xb,%eax 23: 0f 01 c1 vmcall * 26: e9 3a ff ff ff jmp 0xffffff65 <-- trapping instruction 2b: e8 81 b2 50 00 call 0x50b2b1 30: 90 nop 31: 0f 0b ud2 33: 48 89 df mov %rbx,%rdi 36: e8 a6 91 b3 00 call 0xb391e1 3b: e9 .byte 0xe9