syzbot


KASAN: use-after-free Read in snd_rawmidi_transmit

Status: upstream: reported on 2024/07/18 16:26
Reported-by: syzbot+be163a8f8d6c517e20ea@syzkaller.appspotmail.com
First crash: 138d, last: 84d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in snd_rawmidi_transmit usb sound C done done 7 916d 950d 22/28 fixed on 2023/02/24 13:50

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __snd_rawmidi_transmit_peek sound/core/rawmidi.c:1286 [inline]
BUG: KASAN: use-after-free in snd_rawmidi_transmit+0x39a/0x410 sound/core/rawmidi.c:1411
Read of size 1 at addr ffff88807e79c04f by task syz-executor/3569

CPU: 1 PID: 3569 Comm: syz-executor Not tainted 5.15.166-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 __snd_rawmidi_transmit_peek sound/core/rawmidi.c:1286 [inline]
 snd_rawmidi_transmit+0x39a/0x410 sound/core/rawmidi.c:1411
 snd_usbmidi_standard_output+0x1eb/0xf20 sound/usb/midi.c:650
 snd_usbmidi_do_output+0x206/0x520 sound/usb/midi.c:311
 snd_usbmidi_error_timer+0x2a3/0x580 sound/usb/midi.c:362
 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 92 6e 8c f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 77 b8 19 f7 65 8b 05 58 bb c4 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc90002db74a0 EFLAGS: 00000206
RAX: 330024c32e45f600 RBX: 1ffff920005b6e98 RCX: ffffffff96867f03
RDX: dffffc0000000000 RSI: ffffffff8a8b2a20 RDI: 0000000000000001
RBP: ffffc90002db7530 R08: ffffffff8186dac0 R09: ffffed100c00760b
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff920005b6e94 R14: ffffc90002db74c0 R15: 0000000000000246
 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
 unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1538 [inline]
 release_pages+0x1b89/0x1f40 mm/swap.c:960
 __pagevec_release+0x80/0xf0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1145
 evict+0x529/0x930 fs/inode.c:622
 __dentry_kill+0x436/0x650 fs/dcache.c:586
 dentry_kill+0xbb/0x290
 dput+0xd8/0x1a0 fs/dcache.c:893
 __fput+0x636/0x8e0 fs/file_table.c:288
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x6a3/0x2480 kernel/exit.c:874
 do_group_exit+0x144/0x310 kernel/exit.c:996
 __do_sys_exit_group kernel/exit.c:1007 [inline]
 __se_sys_exit_group kernel/exit.c:1005 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1005
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f30e98a9ef9
Code: Unable to access opcode bytes at RIP 0x7f30e98a9ecf.
RSP: 002b:00007ffd9521ca78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f30e991bf56 RCX: 00007f30e98a9ef9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000010 R08: 00007ffd9521a816 R09: 00007ffd9521dd30
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd9521dd30
R13: 00007f30e991bee4 R14: 000055556d2f44a8 R15: 00007ffd9521edf0
 </TASK>

Allocated by task 5755:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc_node+0x199/0x390 mm/slub.c:4455
 kmalloc_node include/linux/slab.h:614 [inline]
 kvmalloc_node+0x80/0x140 mm/util.c:619
 kvmalloc include/linux/mm.h:805 [inline]
 kvzalloc include/linux/mm.h:813 [inline]
 snd_rawmidi_runtime_create sound/core/rawmidi.c:162 [inline]
 open_substream+0x2a4/0x6d0 sound/core/rawmidi.c:306
 rawmidi_open_priv+0xc2/0x680 sound/core/rawmidi.c:357
 snd_rawmidi_kernel_open+0x1b3/0x240 sound/core/rawmidi.c:392
 midisynth_use+0xe7/0x2a0 sound/core/seq/seq_midi.c:221
 subscribe_port sound/core/seq/seq_ports.c:412 [inline]
 check_and_subscribe_port+0x604/0xab0 sound/core/seq/seq_ports.c:495
 snd_seq_port_connect+0x284/0x480 sound/core/seq/seq_ports.c:581
 snd_seq_ioctl_subscribe_port+0x31a/0x780 sound/core/seq/seq_clientmgr.c:1490
 snd_seq_oss_midi_open+0x425/0x9c0 sound/core/seq/oss/seq_oss_midi.c:365
 snd_seq_oss_synth_setup_midi+0x114/0x500 sound/core/seq/oss/seq_oss_synth.c:269
 snd_seq_oss_open+0x942/0x1010 sound/core/seq/oss/seq_oss_init.c:261
 odev_open+0x5f/0x90 sound/core/seq/oss/seq_oss.c:128
 chrdev_open+0x54a/0x630 fs/char_dev.c:414
 do_dentry_open+0x807/0xfb0 fs/open.c:826
 do_open fs/namei.c:3608 [inline]
 path_openat+0x2705/0x2f20 fs/namei.c:3742
 do_filp_open+0x21c/0x460 fs/namei.c:3769
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 5755:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kfree+0xf1/0x270 mm/slub.c:4559
 snd_rawmidi_runtime_free sound/core/rawmidi.c:176 [inline]
 close_substream+0x390/0x600 sound/core/rawmidi.c:528
 rawmidi_release_priv+0xf1/0x180 sound/core/rawmidi.c:547
 snd_rawmidi_kernel_release+0x42/0xa0 sound/core/rawmidi.c:564
 unsubscribe_port sound/core/seq/seq_ports.c:437 [inline]
 __delete_and_unsubscribe_port+0x2c5/0x470 sound/core/seq/seq_ports.c:537
 snd_seq_port_disconnect+0x4ab/0x5d0 sound/core/seq/seq_ports.c:616
 snd_seq_ioctl_unsubscribe_port+0x31a/0x780 sound/core/seq/seq_clientmgr.c:1535
 snd_seq_oss_midi_close+0x348/0x760 sound/core/seq/oss/seq_oss_midi.c:413
 snd_seq_oss_synth_cleanup+0x16b/0x580 sound/core/seq/oss/seq_oss_synth.c:307
 snd_seq_oss_release+0xf2/0x300 sound/core/seq/oss/seq_oss_init.c:415
 odev_release+0x52/0x70 sound/core/seq/oss/seq_oss.c:144
 __fput+0x3fe/0x8e0 fs/file_table.c:280
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88807e79c000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 79 bytes inside of
 4096-byte region [ffff88807e79c000, ffff88807e79d000)
The buggy address belongs to the page:
page:ffffea0001f9e600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e798
head:ffffea0001f9e600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888017042140
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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5755, ts 236564008863, free_ts 236354680713
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 __kmalloc_node+0x1fa/0x390 mm/slub.c:4451
 kmalloc_node include/linux/slab.h:614 [inline]
 kvmalloc_node+0x80/0x140 mm/util.c:619
 kvmalloc include/linux/mm.h:805 [inline]
 kvzalloc include/linux/mm.h:813 [inline]
 snd_rawmidi_runtime_create sound/core/rawmidi.c:162 [inline]
 open_substream+0x2a4/0x6d0 sound/core/rawmidi.c:306
 rawmidi_open_priv+0xc2/0x680 sound/core/rawmidi.c:357
 snd_rawmidi_kernel_open+0x1b3/0x240 sound/core/rawmidi.c:392
 midisynth_use+0xe7/0x2a0 sound/core/seq/seq_midi.c:221
 subscribe_port sound/core/seq/seq_ports.c:412 [inline]
 check_and_subscribe_port+0x604/0xab0 sound/core/seq/seq_ports.c:495
 snd_seq_port_connect+0x284/0x480 sound/core/seq/seq_ports.c:581
 snd_seq_ioctl_subscribe_port+0x31a/0x780 sound/core/seq/seq_clientmgr.c:1490
 snd_seq_oss_midi_open+0x425/0x9c0 sound/core/seq/oss/seq_oss_midi.c:365
 snd_seq_oss_synth_setup_midi+0x114/0x500 sound/core/seq/oss/seq_oss_synth.c:269
 snd_seq_oss_open+0x942/0x1010 sound/core/seq/oss/seq_oss_init.c:261
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 __vunmap+0x8d4/0xa20 mm/vmalloc.c:2621
 btf_free kernel/bpf/btf.c:1513 [inline]
 btf_parse kernel/bpf/btf.c:4390 [inline]
 btf_new_fd+0x57e/0x920 kernel/bpf/btf.c:5920
 __sys_bpf+0x486/0x670 kernel/bpf/syscall.c:4696
 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88807e79bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807e79bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807e79c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff88807e79c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807e79c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	9c                   	pushf
   1:	8f 44 24 20          	pop    0x20(%rsp)
   5:	42 80 3c 23 00       	cmpb   $0x0,(%rbx,%r12,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 92 6e 8c f7       	call   0xf78c6ea6
  14:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  19:	75 4e                	jne    0x69
  1b:	41 f7 c7 00 02 00 00 	test   $0x200,%r15d
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 77 b8 19 f7       	call   0xf719b8a6 <-- trapping instruction
  2f:	65 8b 05 58 bb c4 75 	mov    %gs:0x75c4bb58(%rip),%eax        # 0x75c4bb8e
  36:	85 c0                	test   %eax,%eax
  38:	74 3f                	je     0x79
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/09 18:24 linux-5.15.y 14e468424d3e 073f8be2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in snd_rawmidi_transmit
2024/08/17 07:38 linux-5.15.y 7e89efd3ae1c dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in snd_rawmidi_transmit
2024/07/29 05:32 linux-5.15.y 7e89efd3ae1c 46eb10b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in snd_rawmidi_transmit
2024/07/18 16:25 linux-5.15.y 7c6d66f0266f 71884c12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in snd_rawmidi_transmit
* Struck through repros no longer work on HEAD.