| Message ID | 20210709142418.453-1-paskripkin@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | net: qcom/emac: fix UAF in emac_remove | expand |
On Fri, Jul 9, 2021 at 9:24 AM Pavel Skripkin <paskripkin@gmail.com> wrote: > > adpt is netdev private data and it cannot be > used after free_netdev() call. Using adpt after free_netdev() > can cause UAF bug. Fix it by moving free_netdev() at the end of the > function. Please spell out what "UAF" means, thanks. If you fix that, then Acked-by: Timur Tabi <timur@kernel.org> Thanks.
On Sat, 10 Jul 2021 00:02:26 -0500 Timur Tabi <timur@kernel.org> wrote: > On Fri, Jul 9, 2021 at 9:24 AM Pavel Skripkin <paskripkin@gmail.com> > wrote: > > > > adpt is netdev private data and it cannot be > > used after free_netdev() call. Using adpt after free_netdev() > > can cause UAF bug. Fix it by moving free_netdev() at the end of the > > function. > > Please spell out what "UAF" means, thanks. If you fix that, then > > Acked-by: Timur Tabi <timur@kernel.org> > > Thanks. Hi, Timur! Thank you for feedback. David has already applied this pacth. So, should I send v2 or maybe revert + v2? I haven't been in such situations yet :) With regards, Pavel Skripkin
diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c b/drivers/net/ethernet/qualcomm/emac/emac.c index 8543bf3c3484..ad655f0a4965 100644 --- a/drivers/net/ethernet/qualcomm/emac/emac.c +++ b/drivers/net/ethernet/qualcomm/emac/emac.c @@ -735,12 +735,13 @@ static int emac_remove(struct platform_device *pdev) put_device(&adpt->phydev->mdio.dev); mdiobus_unregister(adpt->mii_bus); - free_netdev(netdev); if (adpt->phy.digital) iounmap(adpt->phy.digital); iounmap(adpt->phy.base); + free_netdev(netdev); + return 0; }
adpt is netdev private data and it cannot be used after free_netdev() call. Using adpt after free_netdev() can cause UAF bug. Fix it by moving free_netdev() at the end of the function. Fixes: 54e19bc74f33 ("net: qcom/emac: do not use devm on internal phy pdev") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- drivers/net/ethernet/qualcomm/emac/emac.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)