* general protection fault in snd_usb_create_mixer
@ 2019-11-21 15:25 syzbot
2019-11-21 20:49 ` Dan Carpenter
0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2019-11-21 15:25 UTC (permalink / raw)
To: alsa-devel, andreyknvl, benquike, dan.carpenter, g, gregkh,
linux-kernel, linux-usb, perex, syzkaller-bugs, tiwai, wang6495
Hello,
syzbot found the following crash on:
HEAD commit: 46178223 usb: gadget: add raw-gadget interface
git tree: https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=176f9836e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=99c88c44660624e7
dashboard link: https://syzkaller.appspot.com/bug?extid=a36ab65c6653d7ccdd62
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1447d3bae00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17ef3a86e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a36ab65c6653d7ccdd62@syzkaller.appspotmail.com
usb 1-1: 208:241 : does not exist
usb 1-1: 208:242 : does not exist
usb 1-1: 208:243 : does not exist
usb 1-1: 208:244 : does not exist
usb 1-1: 208:245 : does not exist
usb 1-1: 208:246 : does not exist
usb 1-1: 208:247 : does not exist
usb 1-1: 208:248 : does not exist
usb 1-1: 208:249 : does not exist
usb 1-1: 208:250 : does not exist
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:snd_usb_mixer_controls_badd sound/usb/mixer.c:2931 [inline]
RIP: 0010:snd_usb_create_mixer+0xbb9/0x1890 sound/usb/mixer.c:3441
Code: ee e8 9b 23 a6 fc 41 39 ee 74 a4 e8 a1 22 a6 fc 48 8b 7c 24 28 89 ee
e8 25 59 b4 fe 48 8d 78 10 48 89 c3 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28
84 c0 74 08 3c 03 0f 8e 2f 09 00 00 8b 6b 10 bf 01
RSP: 0018:ffff8881d932f0a0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff834c5dac
RDX: 0000000000000000 RSI: ffffffff834c5e1b RDI: 0000000000000010
RBP: 0000000000000021 R08: ffff8881da24e000 R09: fffffbfff11aadb5
R10: fffffbfff11aadb4 R11: ffffffff88d56da7 R12: 00000000000000da
R13: dffffc0000000000 R14: 00000000000000d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881db300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043f100 CR3: 0000000006c21000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
usb_audio_probe+0xc76/0x2010 sound/usb/card.c:653
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2202
usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2202
usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537
hub_port_connect drivers/usb/core/hub.c:5184 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5324 [inline]
port_event drivers/usb/core/hub.c:5470 [inline]
hub_event+0x1df8/0x3800 drivers/usb/core/hub.c:5552
process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
worker_thread+0x96/0xe20 kernel/workqueue.c:2415
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 1d30a29898ec11e8 ]---
RIP: 0010:snd_usb_mixer_controls_badd sound/usb/mixer.c:2931 [inline]
RIP: 0010:snd_usb_create_mixer+0xbb9/0x1890 sound/usb/mixer.c:3441
Code: ee e8 9b 23 a6 fc 41 39 ee 74 a4 e8 a1 22 a6 fc 48 8b 7c 24 28 89 ee
e8 25 59 b4 fe 48 8d 78 10 48 89 c3 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28
84 c0 74 08 3c 03 0f 8e 2f 09 00 00 8b 6b 10 bf 01
RSP: 0018:ffff8881d932f0a0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff834c5dac
RDX: 0000000000000000 RSI: ffffffff834c5e1b RDI: 0000000000000010
RBP: 0000000000000021 R08: ffff8881da24e000 R09: fffffbfff11aadb5
R10: fffffbfff11aadb4 R11: ffffffff88d56da7 R12: 00000000000000da
R13: dffffc0000000000 R14: 00000000000000d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881db300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043f100 CR3: 0000000006c21000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: general protection fault in snd_usb_create_mixer
2019-11-21 15:25 general protection fault in snd_usb_create_mixer syzbot
@ 2019-11-21 20:49 ` Dan Carpenter
2019-11-22 11:28 ` Takashi Iwai
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2019-11-21 20:49 UTC (permalink / raw)
To: syzbot
Cc: alsa-devel, andreyknvl, benquike, g, gregkh, linux-kernel,
linux-usb, perex, syzkaller-bugs, tiwai, wang6495
On Thu, Nov 21, 2019 at 07:25:09AM -0800, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 46178223 usb: gadget: add raw-gadget interface
> git tree: https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=176f9836e00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=99c88c44660624e7
> dashboard link: https://syzkaller.appspot.com/bug?extid=a36ab65c6653d7ccdd62
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1447d3bae00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17ef3a86e00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+a36ab65c6653d7ccdd62@syzkaller.appspotmail.com
>
> usb 1-1: 208:241 : does not exist
> usb 1-1: 208:242 : does not exist
> usb 1-1: 208:243 : does not exist
> usb 1-1: 208:244 : does not exist
> usb 1-1: 208:245 : does not exist
> usb 1-1: 208:246 : does not exist
> usb 1-1: 208:247 : does not exist
> usb 1-1: 208:248 : does not exist
> usb 1-1: 208:249 : does not exist
> usb 1-1: 208:250 : does not exist
These error messages are because:
sound/usb/card.c
128 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
129 {
130 struct usb_device *dev = chip->dev;
131 struct usb_host_interface *alts;
132 struct usb_interface_descriptor *altsd;
133 struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
134
135 if (!iface) {
136 dev_err(&dev->dev, "%u:%d : does not exist\n",
137 ctrlif, interface);
138 return -EINVAL;
139 }
"iface" is NULL. The caller ignores the -EINVAL (correctly I think).
Then the NULL dereference happens in snd_usb_mixer_controls_badd()
sound/usb/mixer.c
2903 static int snd_usb_mixer_controls_badd(struct usb_mixer_interface *mixer,
2904 int ctrlif)
2905 {
2906 struct usb_device *dev = mixer->chip->dev;
2907 struct usb_interface_assoc_descriptor *assoc;
2908 int badd_profile = mixer->chip->badd_profile;
2909 struct uac3_badd_profile *f;
2910 const struct usbmix_ctl_map *map;
2911 int p_chmask = 0, c_chmask = 0, st_chmask = 0;
2912 int i;
2913
2914 assoc = usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
2915
2916 /* Detect BADD capture/playback channels from AS EP descriptors */
2917 for (i = 0; i < assoc->bInterfaceCount; i++) {
2918 int intf = assoc->bFirstInterface + i;
2919
2920 struct usb_interface *iface;
2921 struct usb_host_interface *alts;
2922 struct usb_interface_descriptor *altsd;
2923 unsigned int maxpacksize;
2924 char dir_in;
2925 int chmask, num;
2926
2927 if (intf == ctrlif)
2928 continue;
2929
2930 iface = usb_ifnum_to_if(dev, intf);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
iface is not checked.
Should it be "if (!iface) continue;?"
2931 num = iface->num_altsetting;
2932
2933 if (num < 2)
2934 return -EINVAL;
2935
I'm not sure.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: general protection fault in snd_usb_create_mixer
2019-11-21 20:49 ` Dan Carpenter
@ 2019-11-22 11:28 ` Takashi Iwai
0 siblings, 0 replies; 3+ messages in thread
From: Takashi Iwai @ 2019-11-22 11:28 UTC (permalink / raw)
To: Dan Carpenter
Cc: syzbot, alsa-devel, andreyknvl, benquike, g, gregkh,
linux-kernel, linux-usb, perex, syzkaller-bugs, tiwai, wang6495
On Thu, 21 Nov 2019 21:49:56 +0100,
Dan Carpenter wrote:
>
> On Thu, Nov 21, 2019 at 07:25:09AM -0800, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 46178223 usb: gadget: add raw-gadget interface
> > git tree: https://github.com/google/kasan.git usb-fuzzer
> > console output: https://syzkaller.appspot.com/x/log.txt?x=176f9836e00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=99c88c44660624e7
> > dashboard link: https://syzkaller.appspot.com/bug?extid=a36ab65c6653d7ccdd62
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1447d3bae00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17ef3a86e00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+a36ab65c6653d7ccdd62@syzkaller.appspotmail.com
> >
> > usb 1-1: 208:241 : does not exist
> > usb 1-1: 208:242 : does not exist
> > usb 1-1: 208:243 : does not exist
> > usb 1-1: 208:244 : does not exist
> > usb 1-1: 208:245 : does not exist
> > usb 1-1: 208:246 : does not exist
> > usb 1-1: 208:247 : does not exist
> > usb 1-1: 208:248 : does not exist
> > usb 1-1: 208:249 : does not exist
> > usb 1-1: 208:250 : does not exist
>
> These error messages are because:
>
> sound/usb/card.c
> 128 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
> 129 {
> 130 struct usb_device *dev = chip->dev;
> 131 struct usb_host_interface *alts;
> 132 struct usb_interface_descriptor *altsd;
> 133 struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
> 134
> 135 if (!iface) {
> 136 dev_err(&dev->dev, "%u:%d : does not exist\n",
> 137 ctrlif, interface);
> 138 return -EINVAL;
> 139 }
>
> "iface" is NULL. The caller ignores the -EINVAL (correctly I think).
>
> Then the NULL dereference happens in snd_usb_mixer_controls_badd()
>
> sound/usb/mixer.c
> 2903 static int snd_usb_mixer_controls_badd(struct usb_mixer_interface *mixer,
> 2904 int ctrlif)
> 2905 {
> 2906 struct usb_device *dev = mixer->chip->dev;
> 2907 struct usb_interface_assoc_descriptor *assoc;
> 2908 int badd_profile = mixer->chip->badd_profile;
> 2909 struct uac3_badd_profile *f;
> 2910 const struct usbmix_ctl_map *map;
> 2911 int p_chmask = 0, c_chmask = 0, st_chmask = 0;
> 2912 int i;
> 2913
> 2914 assoc = usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
> 2915
> 2916 /* Detect BADD capture/playback channels from AS EP descriptors */
> 2917 for (i = 0; i < assoc->bInterfaceCount; i++) {
> 2918 int intf = assoc->bFirstInterface + i;
> 2919
> 2920 struct usb_interface *iface;
> 2921 struct usb_host_interface *alts;
> 2922 struct usb_interface_descriptor *altsd;
> 2923 unsigned int maxpacksize;
> 2924 char dir_in;
> 2925 int chmask, num;
> 2926
> 2927 if (intf == ctrlif)
> 2928 continue;
> 2929
> 2930 iface = usb_ifnum_to_if(dev, intf);
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> iface is not checked.
>
> Should it be "if (!iface) continue;?"
Right, that should fix the problem. Although the interface number
referred in snd_usb_mixer_controls_badd() can be different from the
one checked in snd_usb_create_stream(), the culprit is the missing
NULL check there.
thanks,
Takashi
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-11-22 11:28 UTC | newest]
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2019-11-21 15:25 general protection fault in snd_usb_create_mixer syzbot
2019-11-21 20:49 ` Dan Carpenter
2019-11-22 11:28 ` Takashi Iwai
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