================================================================== BUG: KASAN: use-after-free in __snd_rawmidi_transmit_peek+0x261/0x360 sound/core/rawmidi.c:1286 Read of size 1 at addr ffff8880797d605f by task syz-executor.0/5754 CPU: 0 PID: 5754 Comm: syz-executor.0 Not tainted 5.18.0-rc5-syzkaller-00016-g107c948d1d3e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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/0x467 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:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:qlist_free_all+0x6c/0x1b0 mm/kasan/quarantine.c:171 Code: 00 fc ff df c6 04 08 fb e8 f1 70 ff ff 48 85 db 0f 85 98 00 00 00 9c 58 f6 c4 02 0f 85 0b 01 00 00 48 85 db 74 01 fb 48 85 ed <0f> 84 d2 00 00 00 48 89 eb 4d 85 e4 4d 89 e7 74 7d 49 63 87 80 00 RSP: 0018:ffffc900061a79e0 EFLAGS: 00000282 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1b6fbc1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880774e3d40 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817ebcc8 R11: 000000000000003f R12: 0000000000000000 R13: ffff888020490000 R14: ffff888020490000 R15: ffff888010c40700 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc mm/slab.c:3316 [inline] __kmem_cache_alloc_lru mm/slab.c:3493 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3513 kmem_cache_zalloc include/linux/slab.h:704 [inline] taskstats_tgid_alloc kernel/taskstats.c:562 [inline] taskstats_exit+0x5c6/0xb50 kernel/taskstats.c:601 do_exit+0x887/0x2a00 kernel/exit.c:780 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x22df/0x24c0 kernel/signal.c:2864 arch_do_signal_or_restart+0x82/0x20f0 arch/x86/kernel/signal.c:867 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f16660ade11 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:00007ffde19933f0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f166619bf60 RCX: 00007f16660ade11 RDX: 00007ffde1993430 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f166619d960 R08: 0000000000000000 R09: 00007ffde19b6080 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000002dd08 R13: 00007ffde1993540 R14: 00007ffde1993560 R15: 0000000000000032 Allocated by task 5759: 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:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524 kmalloc_node include/linux/slab.h:604 [inline] kvmalloc_node+0x3e/0x190 mm/util.c:580 kvmalloc include/linux/slab.h:731 [inline] kvzalloc include/linux/slab.h:739 [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+0x4a1/0x11e0 fs/open.c:824 do_open fs/namei.c:3476 [inline] path_openat+0x1c71/0x2910 fs/namei.c:3609 do_filp_open+0x1aa/0x400 fs/namei.c:3636 do_sys_openat2+0x16d/0x4c0 fs/open.c:1213 do_sys_open fs/open.c:1229 [inline] __do_sys_openat fs/open.c:1245 [inline] __se_sys_openat fs/open.c:1240 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1240 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+0x44/0xae Freed by task 5759: 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:366 [inline] ____kasan_slab_free+0x13d/0x180 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3439 [inline] kfree+0x113/0x310 mm/slab.c:3810 kvfree+0x42/0x50 mm/util.c:622 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_reset+0x422/0x880 sound/core/seq/oss/seq_oss_synth.c:406 snd_seq_oss_reset+0x6f/0x290 sound/core/seq/oss/seq_oss_init.c:435 snd_seq_oss_release+0x78/0x1a0 sound/core/seq/oss/seq_oss_init.c:412 odev_release+0x4f/0x70 sound/core/seq/oss/seq_oss.c:144 __fput+0x277/0x9d0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 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+0x19/0x60 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff8880797d6000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 95 bytes inside of 4096-byte region [ffff8880797d6000, ffff8880797d7000) The buggy address belongs to the physical page: page:ffffea0001e5f580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x797d6 head:ffffea0001e5f580 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001c92f08 ffffea0001ecbf88 ffff888010c40900 raw: 0000000000000000 ffff8880797d6000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 5759, tgid 5754 (syz-executor.0), ts 186337698637, free_ts 186180468597 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 __alloc_pages_node include/linux/gfp.h:587 [inline] kmem_getpages mm/slab.c:1378 [inline] cache_grow_begin+0x75/0x350 mm/slab.c:2584 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957 ____cache_alloc mm/slab.c:3040 [inline] ____cache_alloc mm/slab.c:3023 [inline] slab_alloc_node mm/slab.c:3241 [inline] kmem_cache_alloc_node_trace+0x518/0x5b0 mm/slab.c:3625 __do_kmalloc_node mm/slab.c:3647 [inline] __kmalloc_node+0x38/0x60 mm/slab.c:3655 kmalloc_node include/linux/slab.h:604 [inline] kvmalloc_node+0x3e/0x190 mm/util.c:580 kvmalloc include/linux/slab.h:731 [inline] kvzalloc include/linux/slab.h:739 [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 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 slab_destroy mm/slab.c:1630 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1650 cache_flusharray mm/slab.c:3411 [inline] ___cache_free+0x34e/0x670 mm/slab.c:3474 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 ____kasan_kmalloc mm/kasan/common.c:481 [inline] __kasan_kmalloc+0xba/0xd0 mm/kasan/common.c:524 kasan_kmalloc include/linux/kasan.h:234 [inline] kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3583 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:714 [inline] snd_seq_port_connect+0x5d/0x540 sound/core/seq/seq_ports.c:565 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_reset+0x48e/0x880 sound/core/seq/oss/seq_oss_synth.c:407 snd_seq_oss_reset+0x6f/0x290 sound/core/seq/oss/seq_oss_init.c:435 snd_seq_oss_release+0x78/0x1a0 sound/core/seq/oss/seq_oss_init.c:412 odev_release+0x4f/0x70 sound/core/seq/oss/seq_oss.c:144 Memory state around the buggy address: ffff8880797d5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880797d5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880797d6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880797d6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880797d6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 3 bytes skipped: 0: df c6 ffreep %st(6) 2: 04 08 add $0x8,%al 4: fb sti 5: e8 f1 70 ff ff callq 0xffff70fb a: 48 85 db test %rbx,%rbx d: 0f 85 98 00 00 00 jne 0xab 13: 9c pushfq 14: 58 pop %rax 15: f6 c4 02 test $0x2,%ah 18: 0f 85 0b 01 00 00 jne 0x129 1e: 48 85 db test %rbx,%rbx 21: 74 01 je 0x24 23: fb sti 24: 48 85 ed test %rbp,%rbp * 27: 0f 84 d2 00 00 00 je 0xff <-- trapping instruction 2d: 48 89 eb mov %rbp,%rbx 30: 4d 85 e4 test %r12,%r12 33: 4d 89 e7 mov %r12,%r15 36: 74 7d je 0xb5 38: 49 rex.WB 39: 63 .byte 0x63 3a: 87 .byte 0x87 3b: 80 .byte 0x80