Message-ID: <0000000000000f7c8105873507b5@google.com>
Date:   Tue, 23 Apr 2019 09:25:05 -0700
From:   syzbot <syzbot+e28a58bb80f4c67a2b89@...kaller.appspotmail.com>
To:     alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        perex@...ex.cz, syzkaller-bugs@...glegroups.com, tiwai@...e.com
Subject: KASAN: slab-out-of-bounds Read in linear_transfer (2)

Hello,

syzbot found the following crash on:

HEAD commit:    bcb67f0f Add linux-next specific files for 20190412
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=134b9867200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=35c479ecf64ba753
dashboard link: https://syzkaller.appspot.com/bug?extid=e28a58bb80f4c67a2b89
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e28a58bb80f4c67a2b89@...kaller.appspotmail.com

RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1779cb06d4
R13: 00000000004c5a84 R14: 00000000004d9f20 R15: 0000000000000004
==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:359 [inline]
BUG: KASAN: slab-out-of-bounds in do_convert sound/core/oss/linear.c:48  
[inline]
BUG: KASAN: slab-out-of-bounds in convert sound/core/oss/linear.c:81  
[inline]
BUG: KASAN: slab-out-of-bounds in linear_transfer  
sound/core/oss/linear.c:110 [inline]
BUG: KASAN: slab-out-of-bounds in linear_transfer+0x6de/0x970  
sound/core/oss/linear.c:88
Read of size 1 at addr ffff88809feae2c0 by task syz-executor.4/32294

CPU: 0 PID: 32294 Comm: syz-executor.4 Not tainted 5.1.0-rc4-next-20190412  
#24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x172/0x1f0 lib/dump_stack.c:113
  print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
  kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
  check_memory_region_inline mm/kasan/generic.c:185 [inline]
  check_memory_region+0x123/0x190 mm/kasan/generic.c:191
  memcpy+0x24/0x50 mm/kasan/common.c:132
  memcpy include/linux/string.h:359 [inline]
  do_convert sound/core/oss/linear.c:48 [inline]
  convert sound/core/oss/linear.c:81 [inline]
  linear_transfer sound/core/oss/linear.c:110 [inline]
  linear_transfer+0x6de/0x970 sound/core/oss/linear.c:88
  snd_pcm_plug_read_transfer+0x1a1/0x2f0 sound/core/oss/pcm_plugin.c:651
  snd_pcm_oss_read2+0x1f0/0x3f0 sound/core/oss/pcm_oss.c:1475
  snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1532 [inline]
  snd_pcm_oss_read+0x53a/0x6a0 sound/core/oss/pcm_oss.c:2752
  __vfs_read+0x8d/0x110 fs/read_write.c:416
  vfs_read+0x194/0x3e0 fs/read_write.c:452
  ksys_read+0x14f/0x2d0 fs/read_write.c:579
  __do_sys_read fs/read_write.c:589 [inline]
  __se_sys_read fs/read_write.c:587 [inline]
  __x64_sys_read+0x73/0xb0 fs/read_write.c:587
  do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c29
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1779cafc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f1779cafc90 RCX: 0000000000458c29
RDX: 0000000000001000 RSI: 0000000020004180 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1779cb06d4
R13: 00000000004c5a84 R14: 00000000004d9f20 R15: 0000000000000004

Allocated by task 32294:
  save_stack+0x45/0xd0 mm/kasan/common.c:75
  set_track mm/kasan/common.c:87 [inline]
  __kasan_kmalloc mm/kasan/common.c:497 [inline]
  __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
  kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511
  __do_kmalloc_node mm/slab.c:3686 [inline]
  __kmalloc_node+0x4e/0x70 mm/slab.c:3693
  kmalloc_node include/linux/slab.h:590 [inline]
  kvmalloc_node+0x68/0x100 mm/util.c:430
  kvmalloc include/linux/mm.h:637 [inline]
  kvzalloc include/linux/mm.h:645 [inline]
  snd_pcm_plugin_alloc+0x585/0x770 sound/core/oss/pcm_plugin.c:70
  snd_pcm_plug_alloc+0x148/0x330 sound/core/oss/pcm_plugin.c:129
  snd_pcm_oss_change_params_locked+0x2110/0x3750  
sound/core/oss/pcm_oss.c:1039
  snd_pcm_oss_change_params+0x7b/0xd0 sound/core/oss/pcm_oss.c:1102
  snd_pcm_oss_get_active_substream+0x136/0x190 sound/core/oss/pcm_oss.c:1119
  snd_pcm_oss_get_rate sound/core/oss/pcm_oss.c:1769 [inline]
  snd_pcm_oss_set_rate sound/core/oss/pcm_oss.c:1761 [inline]
  snd_pcm_oss_ioctl+0x8f7/0x3430 sound/core/oss/pcm_oss.c:2608
  vfs_ioctl fs/ioctl.c:46 [inline]
  file_ioctl fs/ioctl.c:509 [inline]
  do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696
  ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
  __do_sys_ioctl fs/ioctl.c:720 [inline]
  __se_sys_ioctl fs/ioctl.c:718 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
  do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88809feae0c0
  which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of
  512-byte region [ffff88809feae0c0, ffff88809feae2c0)
The buggy address belongs to the page:
page:ffffea00027fab80 count:1 mapcount:0 mapping:ffff88812c3f0940 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00025e4188 ffffea00026f3588 ffff88812c3f0940
raw: 0000000000000000 ffff88809feae0c0 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff88809feae180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff88809feae200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff88809feae280: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                            ^
  ffff88809feae300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
  ffff88809feae380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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