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: 51d, last: 21d
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 829d 863d 22/27 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 ffff888077500013 by task syz.2.153/4428

CPU: 1 PID: 4428 Comm: syz.2.153 Not tainted 5.15.164-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 f2 90 8d f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 97 c6 1a f7 65 8b 05 58 cb c5 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc90003327b60 EFLAGS: 00000206
RAX: 9471c08eb1d62000 RBX: 1ffff92000664f70 RCX: ffffffff91467f03
RDX: dffffc0000000000 RSI: ffffffff8a8b2a00 RDI: 0000000000000001
RBP: ffffc90003327bf0 R08: ffffffff8186e200 R09: ffffed100364b002
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000664f6c R14: ffffc90003327b80 R15: 0000000000000246
 raw_ioctl+0x256a/0x3c90
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 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: 0033:0x7fbbc0502a7b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fbbbe97cf10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fbbc0502a7b
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000005
RBP: 00007fbbbe97dfe0 R08: 0000000000000000 R09: 00322e6364755f79
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbbbe97cfb0 R14: 00000000200006c0 R15: 00007fbbc07ca3f0
 </TASK>

Allocated by task 4434:
 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 4434:
 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_reset+0x3c2/0xa20 sound/core/seq/oss/seq_oss_synth.c:406
 snd_seq_oss_reset+0x57/0x240 sound/core/seq/oss/seq_oss_init.c:436
 snd_seq_oss_release+0xea/0x300 sound/core/seq/oss/seq_oss_init.c:413
 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:164
 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 ffff888077500000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 19 bytes inside of
 4096-byte region [ffff888077500000, ffff888077501000)
The buggy address belongs to the page:
page:ffffea0001dd4000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77500
head:ffffea0001dd4000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888011c42140
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 4434, ts 106614324552, free_ts 106593042983
 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
 free_slab mm/slub.c:2015 [inline]
 discard_slab mm/slub.c:2021 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507
 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587
 do_slab_free mm/slub.c:3487 [inline]
 ___cache_free+0xe3/0x100 mm/slub.c:3506
 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
 getname_flags+0xb8/0x4e0 fs/namei.c:138
 user_path_at_empty+0x2a/0x180 fs/namei.c:2882
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x106/0x3b0 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:411 [inline]
 __se_sys_newfstatat fs/stat.c:405 [inline]
 __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405
 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:
 ffff8880774fff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880774fff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888077500000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888077500080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888077500100: 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 f2 90 8d f7       	call   0xf78d9106
  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 97 c6 1a f7       	call   0xf71ac6c6 <-- trapping instruction
  2f:	65 8b 05 58 cb c5 75 	mov    %gs:0x75c5cb58(%rip),%eax        # 0x75c5cb8e
  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 (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.