Hi David, one more small comment On 4/16/22 10:48, David Kahurani wrote:
Reads that are lesser than the requested size lead to uninit-value bugs.
In this particular case a variable which was supposed to be initialized
after a read is left uninitialized after a partial read.
Qualify such reads as errors and handle them correctly and while at it
convert the reader functions to return zero on success for easier error
handling.
Fixes: e2ca90c276e1 ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to
gigabit ethernet adapter driver")
Signed-off-by: David Kahurani <k.kahurani@xxxxxxxxx>
Reported-and-tested-by: syzbot+d3dbdf31fbe9d8f5f311@xxxxxxxxxxxxxxxxxxxxxxxxx
---
[code snip]
@@ -1295,6 +1439,7 @@ static int ax88179_led_setting(struct usbnet *dev) static void ax88179_get_mac_addr(struct usbnet *dev) { u8 mac[ETH_ALEN]; + int ret;memset(mac, 0, sizeof(mac)); @@ -1303,8 +1448,12 @@ static void ax88179_get_mac_addr(struct usbnet *dev)netif_dbg(dev, ifup, dev->net, "MAC address read from device tree"); } else { - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN, - ETH_ALEN, mac); + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN, + ETH_ALEN, mac); + + if (ret) + netdev_dbg(dev->net, "Failed to read NODE_ID: %d", ret); + netif_dbg(dev, ifup, dev->net, "MAC address read from ASIX chip"); }
This message sequence is confusing.In case of ax88179_read_cmd() failure mac read from device actually failed, but message says, that it was successfully finished.
With regards, Pavel Skripkin
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