| Message ID | 20220106225716.7425-1-paskripkin@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | net: mcs7830: handle usb read errors properly | expand |
Hello: This patch was applied to netdev/net.git (master) by Jakub Kicinski <kuba@kernel.org>: On Fri, 7 Jan 2022 01:57:16 +0300 you wrote: > Syzbot reported uninit value in mcs7830_bind(). The problem was in > missing validation check for bytes read via usbnet_read_cmd(). > > usbnet_read_cmd() internally calls usb_control_msg(), that returns > number of bytes read. Code should validate that requested number of bytes > was actually read. > > [...] Here is the summary with links: - net: mcs7830: handle usb read errors properly https://git.kernel.org/netdev/net/c/d668769eb9c5 You are awesome, thank you!
diff --git a/drivers/net/usb/mcs7830.c b/drivers/net/usb/mcs7830.c index 326cc4e749d8..fdda0616704e 100644 --- a/drivers/net/usb/mcs7830.c +++ b/drivers/net/usb/mcs7830.c @@ -108,8 +108,16 @@ static const char driver_name[] = "MOSCHIP usb-ethernet driver"; static int mcs7830_get_reg(struct usbnet *dev, u16 index, u16 size, void *data) { - return usbnet_read_cmd(dev, MCS7830_RD_BREQ, MCS7830_RD_BMREQ, - 0x0000, index, data, size); + int ret; + + ret = usbnet_read_cmd(dev, MCS7830_RD_BREQ, MCS7830_RD_BMREQ, + 0x0000, index, data, size); + if (ret < 0) + return ret; + else if (ret < size) + return -ENODATA; + + return ret; } static int mcs7830_set_reg(struct usbnet *dev, u16 index, u16 size, const void *data)
Syzbot reported uninit value in mcs7830_bind(). The problem was in missing validation check for bytes read via usbnet_read_cmd(). usbnet_read_cmd() internally calls usb_control_msg(), that returns number of bytes read. Code should validate that requested number of bytes was actually read. So, this patch adds missing size validation check inside mcs7830_get_reg() to prevent uninit value bugs CC: Arnd Bergmann <arnd@arndb.de> Reported-and-tested-by: syzbot+003c0a286b9af5412510@syzkaller.appspotmail.com Fixes: 2a36d7083438 ("USB: driver for mcs7830 (aka DeLOCK) USB ethernet adapter") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- @Arnd, I am not sure about mcs7830_get_rev() function. Is get_reg(22, 2) == 1 valid read? If so, I think, we should call usbnet_read_cmd() directly here, since other callers care only about negative error values. Thanks --- drivers/net/usb/mcs7830.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)