@@ -30,10 +30,13 @@ static int aqc111_read_cmd_nopm(struct usbnet *dev, u8 cmd, u16 value,
ret = usbnet_read_cmd_nopm(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_DEVICE, value, index, data, size);
- if (unlikely(ret < 0))
+ if (unlikely(ret < size)) {
+ ret = ret < 0 ? ret : -ENODATA;
+
netdev_warn(dev->net,
"Failed to read(0x%x) reg index 0x%04x: %d\n",
cmd, index, ret);
+ }
return ret;
}
@@ -46,10 +49,13 @@ static int aqc111_read_cmd(struct usbnet *dev, u8 cmd, u16 value,
ret = usbnet_read_cmd(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_DEVICE, value, index, data, size);
- if (unlikely(ret < 0))
+ if (unlikely(ret < size)) {
+ ret = ret < 0 ? ret : -ENODATA;
+
netdev_warn(dev->net,
"Failed to read(0x%x) reg index 0x%04x: %d\n",
cmd, index, ret);
+ }
return ret;
}
Syzkaller, courtesy of syzbot, identified an error (see report [1]) in aqc111 driver, caused by incomplete sanitation of usb read calls' results. This problem is quite similar to the one fixed in commit 920a9fa27e78 ("net: asix: add proper error handling of usb read errors"). For instance, usbnet_read_cmd() may read fewer than 'size' bytes, even if the caller expected the full amount, and aqc111_read_cmd() will not check its result properly. As [1] shows, this may lead to MAC address in aqc111_bind() being only partly initialized, triggering KMSAN warnings. Fix the issue by verifying that the number of bytes read is as expected and not less. [1] Partial syzbot report: BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:208 [inline] BUG: KMSAN: uninit-value in usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830 is_valid_ether_addr include/linux/etherdevice.h:208 [inline] usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x4d1/0xd90 drivers/base/dd.c:658 __driver_probe_device+0x268/0x380 drivers/base/dd.c:800 ... Uninit was stored to memory at: dev_addr_mod+0xb0/0x550 net/core/dev_addr_lists.c:582 __dev_addr_set include/linux/netdevice.h:4874 [inline] eth_hw_addr_set include/linux/etherdevice.h:325 [inline] aqc111_bind+0x35f/0x1150 drivers/net/usb/aqc111.c:717 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 ... Uninit was stored to memory at: ether_addr_copy include/linux/etherdevice.h:305 [inline] aqc111_read_perm_mac drivers/net/usb/aqc111.c:663 [inline] aqc111_bind+0x794/0x1150 drivers/net/usb/aqc111.c:713 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] ... Local variable buf.i created at: aqc111_read_perm_mac drivers/net/usb/aqc111.c:656 [inline] aqc111_bind+0x221/0x1150 drivers/net/usb/aqc111.c:713 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772 Reported-by: syzbot+3b6b9ff7b80430020c7b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3b6b9ff7b80430020c7b Tested-by: syzbot+3b6b9ff7b80430020c7b@syzkaller.appspotmail.com Fixes: df2d59a2ab6c ("net: usb: aqc111: Add support for getting and setting of MAC address") Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> --- P.S. In aqc111 there are many calls to aqc111_read_cmd[_nopm] functions in other parts of the driver and most of them are not checked at all. I've chosen to forego error handling of them, as it seems it's missing deliberately. Correct me if I am wrong. drivers/net/usb/aqc111.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)