vkms_vblank_simulate: vblank timer overrun ================================================================== 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 ffff888030798018 by task modprobe/6735 CPU: 3 UID: 0 PID: 6735 Comm: modprobe Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #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:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:557 kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire kernel/locking/lockdep.c:5840 [inline] lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5823 __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: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:254 [inline] call_irq_handler arch/x86/kernel/irq.c:266 [inline] __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:292 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:285 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:handle_mm_fault+0x4a2/0xad0 mm/memory.c:6338 Code: ff 41 89 dc 31 ff 41 81 e4 00 04 00 00 44 89 e6 e8 43 f2 b1 ff 45 85 e4 0f 84 3d 01 00 00 e8 f5 f6 b1 ff 89 d8 48 83 c4 28 5b <5d> 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc e8 db f6 b1 ff 48 b8 00 RSP: 0000:ffffc90007e2fe88 EFLAGS: 00000292 RAX: 0000000000000200 RBX: 0000000000000006 RCX: ffffffff82095a84 RDX: ffff888053672440 RSI: ffffffff820958fb RDI: ffff888053672bd8 RBP: ffff888053672440 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888034240f10 R14: 0000000000000040 R15: 0000000000000000 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f5c288e5ad6 Code: 48 8d 0d 1d fa 00 00 ba 16 02 00 00 48 8d 35 4c c4 00 00 48 8d 3d 64 c4 00 00 e9 22 fe ff ff 4c 8b 40 10 48 83 c0 18 49 01 f8 <4c> 89 06 eb c0 48 83 3d 9d 81 01 00 00 75 44 48 8d 0d 44 fd 00 00 RSP: 002b:00007ffeacf611f0 EFLAGS: 00010206 RAX: 00007f5c288cecf0 RBX: 00007f5c288cfa28 RCX: 00007f5c288ce510 RDX: 00007f5c288cfa70 RSI: 00007f5c288fb5c0 RDI: 00007f5c288ce000 RBP: 00007ffeacf612a0 R08: 00007f5c288f46e8 R09: 00007f5c288fced0 R10: 00007f5c288dfc40 R11: 000000006fffff41 R12: 00007ffeacf612b0 R13: 00007ffeacf61230 R14: 00007ffeacf61230 R15: 00000000effffef5 Allocated by task 6736: 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:905 [inline] p9_client_create+0xc7/0x11c0 net/9p/client.c:985 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1759 do_new_mount fs/namespace.c:3881 [inline] path_mount+0x14d4/0x1f30 fs/namespace.c:4208 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4432 [inline] __se_sys_mount fs/namespace.c:4409 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4409 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6736: 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:2398 [inline] slab_free mm/slub.c:4656 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4855 p9_client_create+0xa28/0x11c0 net/9p/client.c:1064 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1759 do_new_mount fs/namespace.c:3881 [inline] path_mount+0x14d4/0x1f30 fs/namespace.c:4208 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4432 [inline] __se_sys_mount fs/namespace.c:4409 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4409 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888030798000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888030798000, ffff888030798200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30798 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 ffff88801b442c80 ffffea0000951d00 dead000000000002 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442c80 ffffea0000951d00 dead000000000002 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000c1e601 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 5367, tgid 5367 (udevd), ts 23867042852, free_ts 23212154824 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4970 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2468 [inline] allocate_slab mm/slub.c:2632 [inline] new_slab+0x244/0x340 mm/slub.c:2686 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3872 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3962 __slab_alloc_node mm/slub.c:4037 [inline] slab_alloc_node mm/slub.c:4198 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4367 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] kernfs_fop_open+0x244/0xda0 fs/kernfs/file.c:623 do_dentry_open+0x741/0x1c10 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x1e5e/0x2d40 fs/namei.c:4039 do_filp_open+0x20b/0x470 fs/namei.c:4066 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 page last free pid 5363 tgid 5363 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2725 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0x799/0x14e0 kernel/rcu/tree.c:2824 handle_softirqs+0x216/0x8e0 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:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Memory state around the buggy address: ffff888030797f00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff888030797f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888030798000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888030798080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888030798100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: ff 41 89 incl -0x77(%rcx) 3: dc 31 fdivl (%rcx) 5: ff 41 81 incl -0x7f(%rcx) 8: e4 00 in $0x0,%al a: 04 00 add $0x0,%al c: 00 44 89 e6 add %al,-0x1a(%rcx,%rcx,4) 10: e8 43 f2 b1 ff call 0xffb1f258 15: 45 85 e4 test %r12d,%r12d 18: 0f 84 3d 01 00 00 je 0x15b 1e: e8 f5 f6 b1 ff call 0xffb1f718 23: 89 d8 mov %ebx,%eax 25: 48 83 c4 28 add $0x28,%rsp 29: 5b pop %rbx * 2a: 5d pop %rbp <-- trapping instruction 2b: 41 5c pop %r12 2d: 41 5d pop %r13 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: c3 ret 34: cc int3 35: cc int3 36: cc int3 37: cc int3 38: e8 db f6 b1 ff call 0xffb1f718 3d: 48 rex.W 3e: b8 .byte 0xb8