diff options
| author | Javier Carrasco <javier.carrasco.cruz@gmail.com> | 2023-10-10 00:26:14 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-10-10 20:08:11 -0700 |
| commit | 8f8abb863fa5a4cc18955c6a0e17af0ded3e4a76 (patch) | |
| tree | ac009205a6a7756c133c3ac7c388a83938fff558 | |
| parent | ad98426a88aa8b982b4785760bc56970b3f58281 (diff) | |
net: usb: dm9601: fix uninitialized variable use in dm9601_mdio_read
syzbot has found an uninit-value bug triggered by the dm9601 driver [1].
This error happens because the variable res is not updated if the call
to dm_read_shared_word returns an error. In this particular case -EPROTO
was returned and res stayed uninitialized.
This can be avoided by checking the return value of dm_read_shared_word
and propagating the error if the read operation failed.
[1] https://syzkaller.appspot.com/bug?extid=1f53a30781af65d2c955
Cc: stable@vger.kernel.org
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reported-and-tested-by: syzbot+1f53a30781af65d2c955@syzkaller.appspotmail.com
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Fixes: d0374f4f9c35cdfbee0 ("USB: Davicom DM9601 usbnet driver")
Link: https://lore.kernel.org/r/20231009-topic-dm9601_uninit_mdio_read-v2-1-f2fe39739b6c@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/usb/dm9601.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/net/usb/dm9601.c b/drivers/net/usb/dm9601.c index 48d7d278631e..99ec1d4a972d 100644 --- a/drivers/net/usb/dm9601.c +++ b/drivers/net/usb/dm9601.c @@ -222,13 +222,18 @@ static int dm9601_mdio_read(struct net_device *netdev, int phy_id, int loc) struct usbnet *dev = netdev_priv(netdev); __le16 res; + int err; if (phy_id) { netdev_dbg(dev->net, "Only internal phy supported\n"); return 0; } - dm_read_shared_word(dev, 1, loc, &res); + err = dm_read_shared_word(dev, 1, loc, &res); + if (err < 0) { + netdev_err(dev->net, "MDIO read error: %d\n", err); + return err; + } netdev_dbg(dev->net, "dm9601_mdio_read() phy_id=0x%02x, loc=0x%02x, returns=0x%04x\n", |