From: Oliver Neukum <oneukum@suse.com>
To: syzbot <syzbot+0631d878823ce2411636@syzkaller.appspotmail.com>,
davem@davemloft.net, glider@google.com,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: KMSAN: uninit-value in cdc_ncm_set_dgram_size
Date: Tue, 05 Nov 2019 12:11:56 +0100 [thread overview]
Message-ID: <1572952316.2921.3.camel@suse.com> (raw)
In-Reply-To: <00000000000013c4c1059625a655@google.com>
[-- Attachment #1: Type: text/plain, Size: 948 bytes --]
Am Mittwoch, den 30.10.2019, 12:22 -0700 schrieb syzbot:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 96c6c319 net: kasan: kmsan: support CONFIG_GENERIC_CSUM on..
> git tree: https://github.com/google/kmsan.git master
> console output: https://syzkaller.appspot.com/x/log.txt?x=11f103bce00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=9e324dfe9c7b0360
> dashboard link: https://syzkaller.appspot.com/bug?extid=0631d878823ce2411636
> compiler: clang version 9.0.0 (/home/glider/llvm/clang
> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10dd9774e00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13651a24e00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+0631d878823ce2411636@syzkaller.appspotmail.com
#syz test: https://github.com/google/kmsan.git 96c6c319
[-- Attachment #2: 0001-CDC-NCM-handle-incomplete-transfer-of-MTU.patch --]
[-- Type: text/x-patch, Size: 1146 bytes --]
From 090ac0305bb47da9336c0188e0e59e50ff2243c3 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.com>
Date: Tue, 5 Nov 2019 12:04:44 +0100
Subject: [PATCH] CDC-NCM: handle incomplete transfer of MTU
A malicious device may give half an answer when asked
for its MTU. The driver will proceed after this with
a garbage MTU. Anything but a complete answer must be treated
as an error.
Reported-by: syzbot+0631d878823ce2411636@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/net/usb/cdc_ncm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 00cab3f43a4c..939487a5f4bc 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -579,7 +579,7 @@ static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
0, iface_no, &max_datagram_size, 2);
- if (err < 0) {
+ if (err < 2) {
dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
goto out;
}
--
2.16.4
next prev parent reply other threads:[~2019-11-05 11:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-30 19:22 KMSAN: uninit-value in cdc_ncm_set_dgram_size syzbot
2019-11-04 21:22 ` Bjørn Mork
2019-11-05 11:15 ` Oliver Neukum
2019-11-05 12:25 ` Bjørn Mork
2019-11-05 13:51 ` Oliver Neukum
2019-11-05 13:55 ` Alexander Potapenko
2019-11-05 15:35 ` Greg Kroah-Hartman
2019-11-05 11:11 ` Oliver Neukum [this message]
2019-11-05 12:51 ` syzbot
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