Syzbot reported UAF in port100_send_complete(). The root case is in
missing usb_kill_urb() calls on error handling path of ->probe function.
port100_send_complete() accesses devm allocated memory which will be
freed on probe failure. We should kill this urbs before returning an
error from probe function to prevent reported use-after-free
Fail log:
BUG: KASAN: use-after-free in port100_send_complete+0x16e/0x1a0 drivers/nfc/port100.c:935
Read of size 1 at addr ffff88801bb59540 by task ksoftirqd/2/26
...
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
port100_send_complete+0x16e/0x1a0 drivers/nfc/port100.c:935
__usb_hcd_giveback_urb+0x2b0/0x5c0 drivers/usb/core/hcd.c:1670
...
Allocated by task 1255:
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
alloc_dr drivers/base/devres.c:116 [inline]
devm_kmalloc+0x96/0x1d0 drivers/base/devres.c:823
devm_kzalloc include/linux/device.h:209 [inline]
port100_probe+0x8a/0x1320 drivers/nfc/port100.c:1502
Freed by task 1255:
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+0xff/0x140 mm/kasan/common.c:328
kasan_slab_free include/linux/kasan.h:236 [inline]
__cache_free mm/slab.c:3437 [inline]
kfree+0xf8/0x2b0 mm/slab.c:3794
release_nodes+0x112/0x1a0 drivers/base/devres.c:501
devres_release_all+0x114/0x190 drivers/base/devres.c:530
really_probe+0x626/0xcc0 drivers/base/dd.c:670
Reported-and-tested-by: [email protected]
Fixes: 0347a6ab300a ("NFC: port100: Commands mechanism implementation")
Signed-off-by: Pavel Skripkin <[email protected]>
---
drivers/nfc/port100.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/nfc/port100.c b/drivers/nfc/port100.c
index d7db1a0e6be1..00d8ea6dcb5d 100644
--- a/drivers/nfc/port100.c
+++ b/drivers/nfc/port100.c
@@ -1612,7 +1612,9 @@ static int port100_probe(struct usb_interface *interface,
nfc_digital_free_device(dev->nfc_digital_dev);
error:
+ usb_kill_urb(dev->in_urb);
usb_free_urb(dev->in_urb);
+ usb_kill_urb(dev->out_urb);
usb_free_urb(dev->out_urb);
usb_put_dev(dev->udev);
--
2.35.1
On 08/03/2022 19:50, Pavel Skripkin wrote:
> Syzbot reported UAF in port100_send_complete(). The root case is in
> missing usb_kill_urb() calls on error handling path of ->probe function.
>
> port100_send_complete() accesses devm allocated memory which will be
> freed on probe failure. We should kill this urbs before returning an
> error from probe function to prevent reported use-after-free
>
> Fail log:
>
> BUG: KASAN: use-after-free in port100_send_complete+0x16e/0x1a0 drivers/nfc/port100.c:935
> Read of size 1 at addr ffff88801bb59540 by task ksoftirqd/2/26
> ...
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:88 [inline]
> dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
> print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255
> __kasan_report mm/kasan/report.c:442 [inline]
> kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
> port100_send_complete+0x16e/0x1a0 drivers/nfc/port100.c:935
> __usb_hcd_giveback_urb+0x2b0/0x5c0 drivers/usb/core/hcd.c:1670
>
> ...
>
> Allocated by task 1255:
> 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
> alloc_dr drivers/base/devres.c:116 [inline]
> devm_kmalloc+0x96/0x1d0 drivers/base/devres.c:823
> devm_kzalloc include/linux/device.h:209 [inline]
> port100_probe+0x8a/0x1320 drivers/nfc/port100.c:1502
>
> Freed by task 1255:
> 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+0xff/0x140 mm/kasan/common.c:328
> kasan_slab_free include/linux/kasan.h:236 [inline]
> __cache_free mm/slab.c:3437 [inline]
> kfree+0xf8/0x2b0 mm/slab.c:3794
> release_nodes+0x112/0x1a0 drivers/base/devres.c:501
> devres_release_all+0x114/0x190 drivers/base/devres.c:530
> really_probe+0x626/0xcc0 drivers/base/dd.c:670
>
> Reported-and-tested-by: [email protected]
> Fixes: 0347a6ab300a ("NFC: port100: Commands mechanism implementation")
> Signed-off-by: Pavel Skripkin <[email protected]>
> ---
> drivers/nfc/port100.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/nfc/port100.c b/drivers/nfc/port100.c
> index d7db1a0e6be1..00d8ea6dcb5d 100644
> --- a/drivers/nfc/port100.c
> +++ b/drivers/nfc/port100.c
> @@ -1612,7 +1612,9 @@ static int port100_probe(struct usb_interface *interface,
> nfc_digital_free_device(dev->nfc_digital_dev);
>
> error:
> + usb_kill_urb(dev->in_urb);
> usb_free_urb(dev->in_urb);
> + usb_kill_urb(dev->out_urb);
> usb_free_urb(dev->out_urb);
> usb_put_dev(dev->udev);
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Thanks, this looks good. I think I saw similar patterns also in other
drivers, e.g. pn533. I will check it later, but if you have spare time,
feel free to investigate.
Similar cases (unresolved):
https://syzkaller.appspot.com/bug?extid=1dc8b460d6d48d7ef9ca
https://syzkaller.appspot.com/bug?extid=abd2e0dafb481b621869
https://syzkaller.appspot.com/bug?extid=dbec6695a6565a9c6bc0
Best regards,
Krzysztof
Hi Krzysztof,
On 3/9/22 12:52, Krzysztof Kozlowski wrote:
>
>
> Reviewed-by: Krzysztof Kozlowski <[email protected]>
>
> Thanks, this looks good. I think I saw similar patterns also in other
> drivers, e.g. pn533. I will check it later, but if you have spare time,
> feel free to investigate.
>
> Similar cases (unresolved):
> https://syzkaller.appspot.com/bug?extid=1dc8b460d6d48d7ef9ca
> https://syzkaller.appspot.com/bug?extid=abd2e0dafb481b621869
> https://syzkaller.appspot.com/bug?extid=dbec6695a6565a9c6bc0
>
Thanks for reviewing and pointing out to these bugs! Will take a look
With regards,
Pavel Skripkin
On 3/9/22 21:27, Pavel Skripkin wrote:
> Hi Krzysztof,
>
> On 3/9/22 12:52, Krzysztof Kozlowski wrote:
>>
>>
>> Reviewed-by: Krzysztof Kozlowski <[email protected]>
>>
>> Thanks, this looks good. I think I saw similar patterns also in other
>> drivers, e.g. pn533. I will check it later, but if you have spare time,
>> feel free to investigate.
>>
>> Similar cases (unresolved):
>> https://syzkaller.appspot.com/bug?extid=1dc8b460d6d48d7ef9ca
This one is crazy :) No logs from driver at all. Even can't find where
probe failure comes from (or even is there any failures...)
>> https://syzkaller.appspot.com/bug?extid=abd2e0dafb481b621869
Looks like this patch fixes it.
>> https://syzkaller.appspot.com/bug?extid=dbec6695a6565a9c6bc0
>>
This one is already fixed. Fix bisection is bogus, but this bug is not
reproducible anymore.
With regards,
Pavel Skripkin
Hello:
This patch was applied to netdev/net.git (master)
by Jakub Kicinski <[email protected]>:
On Tue, 8 Mar 2022 21:50:07 +0300 you wrote:
> Syzbot reported UAF in port100_send_complete(). The root case is in
> missing usb_kill_urb() calls on error handling path of ->probe function.
>
> port100_send_complete() accesses devm allocated memory which will be
> freed on probe failure. We should kill this urbs before returning an
> error from probe function to prevent reported use-after-free
>
> [...]
Here is the summary with links:
- NFC: port100: fix use-after-free in port100_send_complete
https://git.kernel.org/netdev/net/c/f80cfe2f2658
You are awesome, thank you!
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