Message ID | 1463944098-7061-1-git-send-email-colin.king@canonical.com |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
Hi Colin, On Sun, May 22, 2016 at 08:08:18PM +0100, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > priv is assigned to NULL however all the error exit paths to label 'free' > dereference priv, causing a null pointer dereference. > > Examination of the code shows that all error exits via the 'free' > label path occur before priv is assigned to netdev_priv(netdev), hence > there is no need to call clk_disable_unprepare and so the location of > the label should be moved to free_netdev statement to avoid this null > dereference on priv. This description is a bit inaccurate. Indeed all 'goto free' above the 'priv = netdev_priv(netdev);' need to skip 'if (priv->clk)' check, but there are two more 'goto free' below that line, and they look correct now, but after this patch they'll leave the clock enabled.
On 22/05/16 20:42, Max Filippov wrote: > Hi Colin, > > On Sun, May 22, 2016 at 08:08:18PM +0100, Colin King wrote: >> From: Colin Ian King <colin.king@canonical.com> >> >> priv is assigned to NULL however all the error exit paths to label 'free' >> dereference priv, causing a null pointer dereference. >> >> Examination of the code shows that all error exits via the 'free' >> label path occur before priv is assigned to netdev_priv(netdev), hence >> there is no need to call clk_disable_unprepare and so the location of >> the label should be moved to free_netdev statement to avoid this null >> dereference on priv. > > This description is a bit inaccurate. Indeed all 'goto free' above the > 'priv = netdev_priv(netdev);' need to skip 'if (priv->clk)' check, but > there are two more 'goto free' below that line, and they look correct > now, but after this patch they'll leave the clock enabled. > Oops, I'll resend a corrected fix tomorrow
diff --git a/drivers/net/ethernet/ethoc.c b/drivers/net/ethernet/ethoc.c index 41b0106..96403a4 100644 --- a/drivers/net/ethernet/ethoc.c +++ b/drivers/net/ethernet/ethoc.c @@ -1241,9 +1241,10 @@ error2: error: mdiobus_unregister(priv->mdio); mdiobus_free(priv->mdio); -free: + if (priv->clk) clk_disable_unprepare(priv->clk); +free: free_netdev(netdev); out: return ret;