| Message ID | 20220808034224.12642-1-linma@zju.edu.cn (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v0] ieee802154/adf7242: defer destroy_workqueue call | expand |
> -----Original Message----- > From: Lin Ma <linma@zju.edu.cn> > Sent: Montag, 8. August 2022 05:42 > To: Hennerich, Michael <Michael.Hennerich@analog.com>; > alex.aring@gmail.com; stefan@datenfreihafen.org; davem@davemloft.net; > edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; linux- > wpan@vger.kernel.org; netdev@vger.kernel.org; linux- > kernel@vger.kernel.org > Cc: Lin Ma <linma@zju.edu.cn> > Subject: [PATCH v0] ieee802154/adf7242: defer destroy_workqueue call > > > There is a possible race condition (use-after-free) like below > > (FREE) | (USE) > adf7242_remove | adf7242_channel > cancel_delayed_work_sync | > destroy_workqueue (1) | adf7242_cmd_rx > | mod_delayed_work (2) > | > > The root cause for this race is that the upper layer (ieee802154) is unaware of > this detaching event and the function adf7242_channel can be called without > any checks. > > To fix this, we can add a flag write at the beginning of adf7242_remove and > add flag check in adf7242_channel. Or we can just defer the destructive > operation like other commit 3e0588c291d6 ("hamradio: defer > ax25 kfree after unregister_netdev") which let the > ieee802154_unregister_hw() to handle the synchronization. This patch takes > the second option. > > Fixes: 58e9683d1475 ("net: ieee802154: adf7242: Fix OCL calibration > runs") > Signed-off-by: Lin Ma <linma@zju.edu.cn> Acked-by: Michael Hennerich <michael.hennerich@analog.com> > --- > drivers/net/ieee802154/adf7242.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ieee802154/adf7242.c > b/drivers/net/ieee802154/adf7242.c > index 6afdf1622944..efcc45aef508 100644 > --- a/drivers/net/ieee802154/adf7242.c > +++ b/drivers/net/ieee802154/adf7242.c > @@ -1310,10 +1310,11 @@ static void adf7242_remove(struct spi_device > *spi) > > debugfs_remove_recursive(lp->debugfs_root); > > + ieee802154_unregister_hw(lp->hw); > + > cancel_delayed_work_sync(&lp->work); > destroy_workqueue(lp->wqueue); > - > - ieee802154_unregister_hw(lp->hw); > + > mutex_destroy(&lp->bmux); > ieee802154_free_hw(lp->hw); > } > -- > 2.36.1
Hello. On 08.08.22 05:42, Lin Ma wrote: > There is a possible race condition (use-after-free) like below > > (FREE) | (USE) > adf7242_remove | adf7242_channel > cancel_delayed_work_sync | > destroy_workqueue (1) | adf7242_cmd_rx > | mod_delayed_work (2) > | > > The root cause for this race is that the upper layer (ieee802154) is > unaware of this detaching event and the function adf7242_channel can > be called without any checks. > > To fix this, we can add a flag write at the beginning of adf7242_remove > and add flag check in adf7242_channel. Or we can just defer the > destructive operation like other commit 3e0588c291d6 ("hamradio: defer > ax25 kfree after unregister_netdev") which let the > ieee802154_unregister_hw() to handle the synchronization. This patch > takes the second option. > > Fixes: 58e9683d1475 ("net: ieee802154: adf7242: Fix OCL calibration > runs") > Signed-off-by: Lin Ma <linma@zju.edu.cn> This patch has been applied to the wpan tree and will be part of the next pull request to net. Thanks! regards Stefan Schmidt
diff --git a/drivers/net/ieee802154/adf7242.c b/drivers/net/ieee802154/adf7242.c index 6afdf1622944..efcc45aef508 100644 --- a/drivers/net/ieee802154/adf7242.c +++ b/drivers/net/ieee802154/adf7242.c @@ -1310,10 +1310,11 @@ static void adf7242_remove(struct spi_device *spi) debugfs_remove_recursive(lp->debugfs_root); + ieee802154_unregister_hw(lp->hw); + cancel_delayed_work_sync(&lp->work); destroy_workqueue(lp->wqueue); - - ieee802154_unregister_hw(lp->hw); + mutex_destroy(&lp->bmux); ieee802154_free_hw(lp->hw); }
There is a possible race condition (use-after-free) like below (FREE) | (USE) adf7242_remove | adf7242_channel cancel_delayed_work_sync | destroy_workqueue (1) | adf7242_cmd_rx | mod_delayed_work (2) | The root cause for this race is that the upper layer (ieee802154) is unaware of this detaching event and the function adf7242_channel can be called without any checks. To fix this, we can add a flag write at the beginning of adf7242_remove and add flag check in adf7242_channel. Or we can just defer the destructive operation like other commit 3e0588c291d6 ("hamradio: defer ax25 kfree after unregister_netdev") which let the ieee802154_unregister_hw() to handle the synchronization. This patch takes the second option. Fixes: 58e9683d1475 ("net: ieee802154: adf7242: Fix OCL calibration runs") Signed-off-by: Lin Ma <linma@zju.edu.cn> --- drivers/net/ieee802154/adf7242.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)