| Message ID | 20240723140434.1330255-1-make24@iscas.ac.cn (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | USB2NET: SR9700: fix uninitialized variable use in sr_mdio_read | expand |
On Tue, Jul 23, 2024 at 10:04:34PM +0800, Ma Ke wrote: > It could lead to error happen because the variable res is not updated if > the call to sr_share_read_word returns an error. In this particular case > error code was returned and res stayed uninitialized. > > This can be avoided by checking the return value of sr_share_read_word > and propagating the error if the read operation failed. > > Fixes: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support") > Signed-off-by: Ma Ke <make24@iscas.ac.cn> You forgot to document how you found this problem. > --- > drivers/net/usb/sr9700.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) Hi, This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree. You are receiving this message because of the following common error(s) as indicated below: - You have marked a patch with a "Fixes:" tag for a commit that is in an older released kernel, yet you do not have a cc: stable line in the signed-off-by area at all, which means that the patch will not be applied to any older kernel releases. To properly fix this, please follow the documented rules in the Documentation/process/stable-kernel-rules.rst file for how to resolve this. If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers. thanks, greg k-h's patch email bot
On Tue, Jul 23, 2024 at 10:04:34PM +0800, Ma Ke wrote: > It could lead to error happen because the variable res is not updated if > the call to sr_share_read_word returns an error. In this particular case > error code was returned and res stayed uninitialized. > > This can be avoided by checking the return value of sr_share_read_word > and propagating the error if the read operation failed. > > Fixes: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support") > Signed-off-by: Ma Ke <make24@iscas.ac.cn> Hi Ma Ke, As this is a fix, with a fixes tag (good!), it should probably be targeted at the net tree (as opposed to net-next). The target tree for networking patches should be included in the Subject. Subject: [PATCH net] ... Looking at git history, it seems that an appropriate prefix for this patch would be net: "net: usb: sr9700: " Subject: [PATCH net] net: usb: sr9700: ... And, skipping ahead, please do consider reading, especially the bit about 24h. https://docs.kernel.org/process/maintainer-netdev.html > --- > drivers/net/usb/sr9700.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/usb/sr9700.c b/drivers/net/usb/sr9700.c > index 0a662e42ed96..d5bc596f4521 100644 > --- a/drivers/net/usb/sr9700.c > +++ b/drivers/net/usb/sr9700.c > @@ -179,6 +179,7 @@ static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc) > struct usbnet *dev = netdev_priv(netdev); > __le16 res; > int rc = 0; > + int err; > > if (phy_id) { > netdev_dbg(netdev, "Only internal phy supported\n"); > @@ -193,7 +194,10 @@ static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc) > if (value & NSR_LINKST) > rc = 1; > } > - sr_share_read_word(dev, 1, loc, &res); > + err = sr_share_read_word(dev, 1, loc, &res); > + if (err < 0) > + return err; > + I agree that this fixes a possible error condition. But I wonder if there are not more similar problems in this file. E.g. the call to sr_read_reg() which seeds value which is used at the top of this hunk. > if (rc == 1) > res = le16_to_cpu(res) | BMSR_LSTATUS; > else > -- > 2.25.1 > >
On Tue, 23 Jul 2024 22:04:34 +0800, Ma Ke wrote: > It could lead to error happen because the variable res is not updated if > the call to sr_share_read_word returns an error. In this particular case > error code was returned and res stayed uninitialized. > > This can be avoided by checking the return value of sr_share_read_word > and propagating the error if the read operation failed. > > Fixes: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support") > Signed-off-by: Ma Ke <make24@iscas.ac.cn> > --- > drivers/net/usb/sr9700.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/usb/sr9700.c b/drivers/net/usb/sr9700.c > index 0a662e42ed96..d5bc596f4521 100644 > --- a/drivers/net/usb/sr9700.c > +++ b/drivers/net/usb/sr9700.c > @@ -179,6 +179,7 @@ static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc) > struct usbnet *dev = netdev_priv(netdev); > __le16 res; > int rc = 0; > + int err; > > if (phy_id) { > netdev_dbg(netdev, "Only internal phy supported\n"); > @@ -193,7 +194,10 @@ static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc) > if (value & NSR_LINKST) > rc = 1; > } > - sr_share_read_word(dev, 1, loc, &res); > + err = sr_share_read_word(dev, 1, loc, &res); > + if (err < 0) > + return err; > + The patch looks good to me. But I think the following sr_read_reg() has the same uninit-value access issue. If sr_read_reg() returns an error, value may be uninitialized: static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc) { [...] /* Access NSR_LINKST bit for link status instead of MII_BMSR */ if (loc == MII_BMSR) { u8 value; sr_read_reg(dev, SR_NSR, &value); if (value & NSR_LINKST) rc = 1; } Why don't we fix it together? Thanks, Shigeru > if (rc == 1) > res = le16_to_cpu(res) | BMSR_LSTATUS; > else > -- > 2.25.1 > >
diff --git a/drivers/net/usb/sr9700.c b/drivers/net/usb/sr9700.c index 0a662e42ed96..d5bc596f4521 100644 --- a/drivers/net/usb/sr9700.c +++ b/drivers/net/usb/sr9700.c @@ -179,6 +179,7 @@ static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc) struct usbnet *dev = netdev_priv(netdev); __le16 res; int rc = 0; + int err; if (phy_id) { netdev_dbg(netdev, "Only internal phy supported\n"); @@ -193,7 +194,10 @@ static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc) if (value & NSR_LINKST) rc = 1; } - sr_share_read_word(dev, 1, loc, &res); + err = sr_share_read_word(dev, 1, loc, &res); + if (err < 0) + return err; + if (rc == 1) res = le16_to_cpu(res) | BMSR_LSTATUS; else
It could lead to error happen because the variable res is not updated if the call to sr_share_read_word returns an error. In this particular case error code was returned and res stayed uninitialized. This can be avoided by checking the return value of sr_share_read_word and propagating the error if the read operation failed. Fixes: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support") Signed-off-by: Ma Ke <make24@iscas.ac.cn> --- drivers/net/usb/sr9700.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)