diff mbox series

[5.12,regression,fix,resend,1/1] brcmfmac: p2p: Fix recently introduced deadlock issue

Message ID 20210405205429.19304-2-hdegoede@redhat.com
State New
Headers show
Series brcmfmac: p2p: Fix recently introduced deadlock issue | expand

Commit Message

Hans de Goede April 5, 2021, 8:54 p.m. UTC
Commit a05829a7222e ("cfg80211: avoid holding the RTNL when calling the
driver") replaced the rtnl_lock parameter passed to various brcmf
functions with just lock, because since that commit it is not just
about the rtnl_lock but also about the wiphy_lock .

During this search/replace the "if (!rtnl_locked)" check in brcmfmac/p2p.c
was accidentally replaced with "if (locked)", dropping the inversion of
the check. This causes the code to now call rtnl_lock() while already
holding the lock, causing a deadlock.

Add back the "!" to the if-condition to fix this.

Cc: Johannes Berg <johannes.berg@intel.com>
Fixes: a05829a7222e ("cfg80211: avoid holding the RTNL when calling the driver")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Kalle Valo April 6, 2021, 10:17 a.m. UTC | #1
Hans de Goede <hdegoede@redhat.com> wrote:

> Commit a05829a7222e ("cfg80211: avoid holding the RTNL when calling the

> driver") replaced the rtnl_lock parameter passed to various brcmf

> functions with just lock, because since that commit it is not just

> about the rtnl_lock but also about the wiphy_lock .

> 

> During this search/replace the "if (!rtnl_locked)" check in brcmfmac/p2p.c

> was accidentally replaced with "if (locked)", dropping the inversion of

> the check. This causes the code to now call rtnl_lock() while already

> holding the lock, causing a deadlock.

> 

> Add back the "!" to the if-condition to fix this.

> 

> Cc: Johannes Berg <johannes.berg@intel.com>

> Fixes: a05829a7222e ("cfg80211: avoid holding the RTNL when calling the driver")

> Signed-off-by: Hans de Goede <hdegoede@redhat.com>


This is already applied:

https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers.git/commit/?id=bd83a2fc05ed323d7ae38443a6d2e253ef1c4237

Patch set to Superseded.

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20210405205429.19304-2-hdegoede@redhat.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Hans de Goede April 6, 2021, 10:29 a.m. UTC | #2
Hi,

On 4/6/21 12:17 PM, Kalle Valo wrote:
> Hans de Goede <hdegoede@redhat.com> wrote:

> 

>> Commit a05829a7222e ("cfg80211: avoid holding the RTNL when calling the

>> driver") replaced the rtnl_lock parameter passed to various brcmf

>> functions with just lock, because since that commit it is not just

>> about the rtnl_lock but also about the wiphy_lock .

>>

>> During this search/replace the "if (!rtnl_locked)" check in brcmfmac/p2p.c

>> was accidentally replaced with "if (locked)", dropping the inversion of

>> the check. This causes the code to now call rtnl_lock() while already

>> holding the lock, causing a deadlock.

>>

>> Add back the "!" to the if-condition to fix this.

>>

>> Cc: Johannes Berg <johannes.berg@intel.com>

>> Fixes: a05829a7222e ("cfg80211: avoid holding the RTNL when calling the driver")

>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

> 

> This is already applied:

> 

> https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers.git/commit/?id=bd83a2fc05ed323d7ae38443a6d2e253ef1c4237


But it is not yet in 5.12-rc6, even though this is a regression fix for a
regression introduced in 5.12. What is the plan to get this into 5.12 ?

Regards,

Hans
diff mbox series

Patch

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 6d30a0fcecea..34cd8a7401fe 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -2439,7 +2439,7 @@  void brcmf_p2p_ifp_removed(struct brcmf_if *ifp, bool locked)
 	vif = ifp->vif;
 	cfg = wdev_to_cfg(&vif->wdev);
 	cfg->p2p.bss_idx[P2PAPI_BSSCFG_DEVICE].vif = NULL;
-	if (locked) {
+	if (!locked) {
 		rtnl_lock();
 		wiphy_lock(cfg->wiphy);
 		cfg80211_unregister_wdev(&vif->wdev);