================================================================== BUG: KASAN: use-after-free in __snd_rawmidi_transmit_peek+0x261/0x360 sound/core/rawmidi.c:1286 Read of size 1 at addr ffff888027a6e050 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.19.0-syzkaller-02972-g200e340f2196 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 __snd_rawmidi_transmit_peek+0x261/0x360 sound/core/rawmidi.c:1286 snd_rawmidi_transmit+0x8d/0xf0 sound/core/rawmidi.c:1411 snd_usbmidi_standard_output+0x264/0xc10 sound/usb/midi.c:650 snd_usbmidi_do_output+0x200/0x510 sound/usb/midi.c:311 snd_usbmidi_error_timer+0x128/0x390 sound/usb/midi.c:362 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline] RIP: 0010:acpi_idle_do_entry+0x1c9/0x240 drivers/acpi/processor_idle.c:555 Code: 89 de e8 9a d3 ff f7 84 db 75 98 e8 91 d7 ff f7 e8 fc 26 06 f8 66 90 e8 85 d7 ff f7 0f 00 2d fe 24 b9 00 e8 79 d7 ff f7 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 c4 d3 ff f7 48 85 db RSP: 0018:ffffc90000177d20 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888011a19d80 RSI: ffffffff897b0247 RDI: 0000000000000000 RBP: ffff888011b16864 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888011b16800 R14: ffff888011b16864 R15: ffff8881460e7804 acpi_idle_enter+0x369/0x510 drivers/acpi/processor_idle.c:692 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:238 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:352 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3e8/0x590 kernel/sched/idle.c:303 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:266 secondary_startup_64_no_verify+0xce/0xdb Allocated by task 9308: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc_node include/linux/slab.h:623 [inline] kvmalloc_node+0x3e/0x190 mm/util.c:613 kvmalloc include/linux/slab.h:750 [inline] kvzalloc include/linux/slab.h:758 [inline] snd_rawmidi_runtime_create sound/core/rawmidi.c:162 [inline] open_substream+0x340/0x8b0 sound/core/rawmidi.c:306 rawmidi_open_priv+0x591/0x6f0 sound/core/rawmidi.c:357 snd_rawmidi_kernel_open+0x1b5/0x270 sound/core/rawmidi.c:392 midisynth_use+0xee/0x270 sound/core/seq/seq_midi.c:215 subscribe_port sound/core/seq/seq_ports.c:412 [inline] check_and_subscribe_port+0x89a/0xb80 sound/core/seq/seq_ports.c:495 snd_seq_port_connect+0x382/0x540 sound/core/seq/seq_ports.c:581 snd_seq_ioctl_subscribe_port+0x1fc/0x400 sound/core/seq/seq_clientmgr.c:1492 snd_seq_kernel_client_ctl+0x102/0x1e0 sound/core/seq/seq_clientmgr.c:2369 snd_seq_oss_midi_open+0x582/0x6e0 sound/core/seq/oss/seq_oss_midi.c:359 snd_seq_oss_synth_setup_midi+0x12d/0x530 sound/core/seq/oss/seq_oss_synth.c:269 snd_seq_oss_open+0x8c3/0xa80 sound/core/seq/oss/seq_oss_init.c:260 odev_open+0x6c/0x90 sound/core/seq/oss/seq_oss.c:128 soundcore_open+0x44e/0x620 sound/sound_core.c:593 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4a1/0x12d0 fs/open.c:878 do_open fs/namei.c:3499 [inline] path_openat+0x1c92/0x28f0 fs/namei.c:3632 do_filp_open+0x1b6/0x400 fs/namei.c:3659 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_compat_sys_openat fs/open.c:1386 [inline] __se_compat_sys_openat fs/open.c:1384 [inline] __ia32_compat_sys_openat+0x13f/0x1f0 fs/open.c:1384 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 9308: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kfree+0xe2/0x4d0 mm/slub.c:4562 kvfree+0x42/0x50 mm/util.c:655 snd_rawmidi_runtime_free sound/core/rawmidi.c:176 [inline] close_substream.part.0+0x185/0x720 sound/core/rawmidi.c:528 close_substream sound/core/rawmidi.c:507 [inline] rawmidi_release_priv+0x192/0x270 sound/core/rawmidi.c:547 snd_rawmidi_kernel_release+0x39/0xd0 sound/core/rawmidi.c:564 midisynth_unuse+0x45/0x80 sound/core/seq/seq_midi.c:244 unsubscribe_port sound/core/seq/seq_ports.c:437 [inline] __delete_and_unsubscribe_port+0x270/0x4c0 sound/core/seq/seq_ports.c:537 snd_seq_port_disconnect+0x41c/0x5d0 sound/core/seq/seq_ports.c:616 snd_seq_ioctl_unsubscribe_port+0x1fc/0x400 sound/core/seq/seq_clientmgr.c:1537 snd_seq_kernel_client_ctl+0x102/0x1e0 sound/core/seq/seq_clientmgr.c:2369 snd_seq_oss_midi_close+0x44f/0x4d0 sound/core/seq/oss/seq_oss_midi.c:404 snd_seq_oss_synth_cleanup+0x32c/0x480 sound/core/seq/oss/seq_oss_synth.c:307 snd_seq_oss_release+0x80/0x1a0 sound/core/seq/oss/seq_oss_init.c:414 odev_release+0x4f/0x70 sound/core/seq/oss/seq_oss.c:144 __fput+0x277/0x9d0 fs/file_table.c:319 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 The buggy address belongs to the object at ffff888027a6e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 80 bytes inside of 4096-byte region [ffff888027a6e000, ffff888027a6f000) The buggy address belongs to the physical page: page:ffffea00009e9a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27a68 head:ffffea00009e9a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888011842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 2971, tgid 2971 (udevd), ts 400825135778, free_ts 400746383011 prep_new_page mm/page_alloc.c:2457 [inline] get_page_from_freelist+0x1298/0x3b80 mm/page_alloc.c:4203 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5431 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x99f/0xe10 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] slab_alloc mm/slub.c:3251 [inline] __kmalloc+0x393/0x470 mm/slub.c:4420 kmalloc include/linux/slab.h:605 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1345 vfs_getattr fs/stat.c:157 [inline] vfs_statx+0x16a/0x390 fs/stat.c:232 vfs_fstatat+0x8c/0xb0 fs/stat.c:255 __do_sys_newfstatat+0x91/0x110 fs/stat.c:425 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3344 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3439 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc_lru+0x31f/0x730 mm/slub.c:3275 __d_alloc+0x32/0x960 fs/dcache.c:1769 d_alloc+0x4a/0x230 fs/dcache.c:1849 d_alloc_parallel+0xe7/0x1af0 fs/dcache.c:2614 __lookup_slow+0x193/0x460 fs/namei.c:1670 lookup_slow fs/namei.c:1702 [inline] walk_component+0x33f/0x5a0 fs/namei.c:1993 link_path_walk.part.0+0x7e6/0xf60 fs/namei.c:2320 link_path_walk fs/namei.c:2245 [inline] path_openat+0x262/0x28f0 fs/namei.c:3628 do_filp_open+0x1b6/0x400 fs/namei.c:3659 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 Memory state around the buggy address: ffff888027a6df00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888027a6df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888027a6e000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888027a6e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027a6e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 89 de mov %ebx,%esi 2: e8 9a d3 ff f7 callq 0xf7ffd3a1 7: 84 db test %bl,%bl 9: 75 98 jne 0xffffffa3 b: e8 91 d7 ff f7 callq 0xf7ffd7a1 10: e8 fc 26 06 f8 callq 0xf8062711 15: 66 90 xchg %ax,%ax 17: e8 85 d7 ff f7 callq 0xf7ffd7a1 1c: 0f 00 2d fe 24 b9 00 verw 0xb924fe(%rip) # 0xb92521 23: e8 79 d7 ff f7 callq 0xf7ffd7a1 28: fb sti 29: f4 hlt * 2a: 9c pushfq <-- trapping instruction 2b: 5b pop %rbx 2c: 81 e3 00 02 00 00 and $0x200,%ebx 32: fa cli 33: 31 ff xor %edi,%edi 35: 48 89 de mov %rbx,%rsi 38: e8 c4 d3 ff f7 callq 0xf7ffd401 3d: 48 85 db test %rbx,%rbx