================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2d90/0x3c40 kernel/locking/lockdep.c:5091 Read of size 8 at addr ffff88805743e818 by task swapper/3/0 CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.14.0-rc3-syzkaller-00180-ga3daad821514 #0 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+0xd9/0x110 mm/kasan/report.c:634 __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+0x61/0xe0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:handle_softirqs+0x1da/0x8f0 kernel/softirq.c:547 Code: 89 44 24 18 48 89 6c 24 10 48 c7 c7 40 74 6b 8b e8 eb 3d db 09 65 66 c7 05 39 ca 87 7e 00 00 e8 9c 87 45 00 fb bb ff ff ff ff <49> c7 c6 c0 b0 e0 8d 41 0f bc dc 83 c3 01 0f 85 a4 00 00 00 e9 b1 RSP: 0018:ffffc90000708f28 EFLAGS: 00000206 RAX: 00000000000ffd56 RBX: 00000000ffffffff RCX: 1ffffffff20c41b1 RDX: 0000000000000000 RSI: ffffffff8b6ceca0 RDI: ffffffff8bd35600 RBP: ffff88801daaa440 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90625117 R11: 0000000000000000 R12: 0000000000000282 R13: 000000000000000a R14: 0000000000000001 R15: 0000000000000000 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 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 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:default_idle+0xf/0x20 arch/x86/kernel/process.c:744 Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d d3 4f 0f 00 fb f4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffffc900001a7e08 EFLAGS: 00000206 RAX: 00000000000ffd53 RBX: 0000000000000003 RCX: ffffffff8b574469 RDX: 0000000000000000 RSI: ffffffff8b6ceca0 RDI: ffffffff8bd35600 RBP: ffffed1003b55488 R08: 0000000000000001 R09: ffffed100d526f85 R10: ffff88806a937c2b R11: 0000000000000000 R12: 0000000000000003 R13: ffff88801daaa440 R14: ffffffff90625110 R15: 0000000000000000 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x329/0x3f0 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x222/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 Allocated by task 29736: 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+0xc8/0x1200 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+0x14e6/0x1f10 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] __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 29736: 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+0xa58/0x1200 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+0x14e6/0x1f10 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] __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805743e800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff88805743e800, ffff88805743ea00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5743c 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 ffffea00041b9700 0000000000000002 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042c80 ffffea00041b9700 0000000000000002 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00015d0f01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 29441, tgid 29441 (syz.2.11248), ts 296419345221, free_ts 279529818497 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_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x23d/0x330 mm/slub.c:2640 ___slab_alloc+0xc5d/0x1720 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] __kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] snd_rawmidi_runtime_create sound/core/rawmidi.c:162 [inline] open_substream+0xec/0x9b0 sound/core/rawmidi.c:345 rawmidi_open_priv+0x4d8/0x6e0 sound/core/rawmidi.c:392 snd_rawmidi_kernel_open+0xb5/0x190 sound/core/rawmidi.c:423 midisynth_subscribe+0xe5/0x350 sound/core/seq/seq_midi.c:178 subscribe_port sound/core/seq/seq_ports.c:438 [inline] check_and_subscribe_port+0x912/0xc00 sound/core/seq/seq_ports.c:520 snd_seq_port_connect+0x2f6/0x550 sound/core/seq/seq_ports.c:596 snd_seq_ioctl_subscribe_port+0x1fe/0x430 sound/core/seq/seq_clientmgr.c:1524 snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2557 page last free pid 28675 tgid 28675 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 vfree+0x174/0x950 mm/vmalloc.c:3383 snd_dma_free_pages+0x51/0x70 sound/core/memalloc.c:132 do_free_pages sound/core/pcm_memory.c:88 [inline] do_free_pages sound/core/pcm_memory.c:83 [inline] snd_pcm_lib_free_pages+0x172/0x390 sound/core/pcm_memory.c:495 do_hw_free sound/core/pcm_native.c:894 [inline] snd_pcm_release_substream.part.0+0x2a8/0x340 sound/core/pcm_native.c:2718 snd_pcm_release_substream+0x5b/0x70 sound/core/pcm_native.c:2712 snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2398 [inline] snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2390 [inline] snd_pcm_oss_release+0x135/0x310 sound/core/oss/pcm_oss.c:2577 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805743e700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805743e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805743e800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805743e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805743e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 89 44 24 18 mov %eax,0x18(%rsp) 4: 48 89 6c 24 10 mov %rbp,0x10(%rsp) 9: 48 c7 c7 40 74 6b 8b mov $0xffffffff8b6b7440,%rdi 10: e8 eb 3d db 09 call 0x9db3e00 15: 65 66 c7 05 39 ca 87 movw $0x0,%gs:0x7e87ca39(%rip) # 0x7e87ca58 1c: 7e 00 00 1f: e8 9c 87 45 00 call 0x4587c0 24: fb sti 25: bb ff ff ff ff mov $0xffffffff,%ebx * 2a: 49 c7 c6 c0 b0 e0 8d mov $0xffffffff8de0b0c0,%r14 <-- trapping instruction 31: 41 0f bc dc bsf %r12d,%ebx 35: 83 c3 01 add $0x1,%ebx 38: 0f 85 a4 00 00 00 jne 0xe2 3e: e9 .byte 0xe9 3f: b1 .byte 0xb1