* [PATCH v2] mac80211: fix race in ieee80211_register_hw()
@ 2020-04-07 10:10 Sumit Garg
2020-04-07 19:25 ` Krishna Chaitanya
0 siblings, 1 reply; 8+ messages in thread
From: Sumit Garg @ 2020-04-07 10:10 UTC (permalink / raw)
To: linux-wireless, johannes
Cc: davem, kuba, kvalo, chaitanya.mgit, netdev, linux-kernel,
matthias.schoepfer, Philipp.Berg, Michael.Weitner,
daniel.thompson, loic.poulain, Sumit Garg, stable
A race condition leading to a kernel crash is observed during invocation
of ieee80211_register_hw() on a dragonboard410c device having wcn36xx
driver built as a loadable module along with a wifi manager in user-space
waiting for a wifi device (wlanX) to be active.
Sequence diagram for a particular kernel crash scenario:
user-space ieee80211_register_hw() ieee80211_tasklet_handler()
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| | |
|<---phy0----wiphy_register() |
|-----iwd if_add---->| |
| |<---IRQ----(RX packet)
| Kernel crash |
| due to unallocated |
| workqueue. |
| | |
| alloc_ordered_workqueue() |
| | |
| Misc wiphy init. |
| | |
| ieee80211_if_add() |
| | |
As evident from above sequence diagram, this race condition isn't specific
to a particular wifi driver but rather the initialization sequence in
ieee80211_register_hw() needs to be fixed. So re-order the initialization
sequence and the updated sequence diagram would look like:
user-space ieee80211_register_hw() ieee80211_tasklet_handler()
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| | |
| alloc_ordered_workqueue() |
| | |
| Misc wiphy init. |
| | |
|<---phy0----wiphy_register() |
|-----iwd if_add---->| |
| |<---IRQ----(RX packet)
| | |
| ieee80211_if_add() |
| | |
Cc: <stable@vger.kernel.org>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
Changes in v2:
- Move rtnl_unlock() just after ieee80211_init_rate_ctrl_alg().
- Update sequence diagrams in commit message for more clarification.
net/mac80211/main.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 4c2b5ba..d497129 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1051,7 +1051,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC;
if (hw->max_signal <= 0) {
result = -EINVAL;
- goto fail_wiphy_register;
+ goto fail_workqueue;
}
}
@@ -1113,7 +1113,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
result = ieee80211_init_cipher_suites(local);
if (result < 0)
- goto fail_wiphy_register;
+ goto fail_workqueue;
if (!local->ops->remain_on_channel)
local->hw.wiphy->max_remain_on_channel_duration = 5000;
@@ -1139,10 +1139,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM;
- result = wiphy_register(local->hw.wiphy);
- if (result < 0)
- goto fail_wiphy_register;
-
/*
* We use the number of queues for feature tests (QoS, HT) internally
* so restrict them appropriately.
@@ -1207,6 +1203,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
goto fail_rate;
}
+ rtnl_unlock();
+
if (local->rate_ctrl) {
clear_bit(IEEE80211_HW_SUPPORTS_VHT_EXT_NSS_BW, hw->flags);
if (local->rate_ctrl->ops->capa & RATE_CTRL_CAPA_VHT_EXT_NSS_BW)
@@ -1254,6 +1252,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
local->sband_allocated |= BIT(band);
}
+ result = wiphy_register(local->hw.wiphy);
+ if (result < 0)
+ goto fail_wiphy_register;
+
+ rtnl_lock();
+
/* add one default STA interface if supported */
if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) &&
!ieee80211_hw_check(hw, NO_AUTO_VIF)) {
@@ -1293,6 +1297,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
#if defined(CONFIG_INET) || defined(CONFIG_IPV6)
fail_ifa:
#endif
+ wiphy_unregister(local->hw.wiphy);
+ fail_wiphy_register:
rtnl_lock();
rate_control_deinitialize(local);
ieee80211_remove_interfaces(local);
@@ -1302,8 +1308,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
ieee80211_led_exit(local);
destroy_workqueue(local->workqueue);
fail_workqueue:
- wiphy_unregister(local->hw.wiphy);
- fail_wiphy_register:
if (local->wiphy_ciphers_allocated)
kfree(local->hw.wiphy->cipher_suites);
kfree(local->int_scan_req);
@@ -1353,8 +1357,8 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
skb_queue_purge(&local->skb_queue_unreliable);
skb_queue_purge(&local->skb_queue_tdls_chsw);
- destroy_workqueue(local->workqueue);
wiphy_unregister(local->hw.wiphy);
+ destroy_workqueue(local->workqueue);
ieee80211_led_exit(local);
kfree(local->int_scan_req);
}
--
2.7.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH v2] mac80211: fix race in ieee80211_register_hw() 2020-04-07 10:10 [PATCH v2] mac80211: fix race in ieee80211_register_hw() Sumit Garg @ 2020-04-07 19:25 ` Krishna Chaitanya 2020-04-09 4:42 ` Sumit Garg 0 siblings, 1 reply; 8+ messages in thread From: Krishna Chaitanya @ 2020-04-07 19:25 UTC (permalink / raw) To: Sumit Garg Cc: linux-wireless, Johannes Berg, David S. Miller, kuba, Kalle Valo, netdev, Linux Kernel Mailing List, Matthias-Peter Schöpfer, Berg Philipp (HAU-EDS), Weitner Michael (HAU-EDS), Daniel Thompson, Loic Poulain, stable On Tue, Apr 7, 2020 at 3:41 PM Sumit Garg <sumit.garg@linaro.org> wrote: > > A race condition leading to a kernel crash is observed during invocation > of ieee80211_register_hw() on a dragonboard410c device having wcn36xx > driver built as a loadable module along with a wifi manager in user-space > waiting for a wifi device (wlanX) to be active. > > Sequence diagram for a particular kernel crash scenario: > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > | | | > |<---phy0----wiphy_register() | > |-----iwd if_add---->| | just a nitpick, a better one would be (iwd: if_add + ap_start) since we need to have 'iwctl ap start' to trigger the interrupts. > | |<---IRQ----(RX packet) > | Kernel crash | > | due to unallocated | > | workqueue. | > | | | > | alloc_ordered_workqueue() | > | | | > | Misc wiphy init. | > | | | > | ieee80211_if_add() | > | | | > > As evident from above sequence diagram, this race condition isn't specific > to a particular wifi driver but rather the initialization sequence in > ieee80211_register_hw() needs to be fixed. So re-order the initialization > sequence and the updated sequence diagram would look like: > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > | | | > | alloc_ordered_workqueue() | > | | | > | Misc wiphy init. | > | | | > |<---phy0----wiphy_register() | > |-----iwd if_add---->| | same as above. > | |<---IRQ----(RX packet) > | | | > | ieee80211_if_add() | > | | | > > Cc: <stable@vger.kernel.org> > Signed-off-by: Sumit Garg <sumit.garg@linaro.org> > --- > > Changes in v2: > - Move rtnl_unlock() just after ieee80211_init_rate_ctrl_alg(). > - Update sequence diagrams in commit message for more clarification. > > net/mac80211/main.c | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) > > diff --git a/net/mac80211/main.c b/net/mac80211/main.c > index 4c2b5ba..d497129 100644 > --- a/net/mac80211/main.c > +++ b/net/mac80211/main.c > @@ -1051,7 +1051,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC; > if (hw->max_signal <= 0) { > result = -EINVAL; > - goto fail_wiphy_register; > + goto fail_workqueue; > } > } > > @@ -1113,7 +1113,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > result = ieee80211_init_cipher_suites(local); > if (result < 0) > - goto fail_wiphy_register; > + goto fail_workqueue; > > if (!local->ops->remain_on_channel) > local->hw.wiphy->max_remain_on_channel_duration = 5000; > @@ -1139,10 +1139,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM; > > - result = wiphy_register(local->hw.wiphy); > - if (result < 0) > - goto fail_wiphy_register; > - > /* > * We use the number of queues for feature tests (QoS, HT) internally > * so restrict them appropriately. > @@ -1207,6 +1203,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > goto fail_rate; > } > > + rtnl_unlock(); > + > if (local->rate_ctrl) { > clear_bit(IEEE80211_HW_SUPPORTS_VHT_EXT_NSS_BW, hw->flags); > if (local->rate_ctrl->ops->capa & RATE_CTRL_CAPA_VHT_EXT_NSS_BW) > @@ -1254,6 +1252,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > local->sband_allocated |= BIT(band); > } > > + result = wiphy_register(local->hw.wiphy); > + if (result < 0) > + goto fail_wiphy_register; > + > + rtnl_lock(); > + > /* add one default STA interface if supported */ > if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) && > !ieee80211_hw_check(hw, NO_AUTO_VIF)) { > @@ -1293,6 +1297,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > #if defined(CONFIG_INET) || defined(CONFIG_IPV6) > fail_ifa: > #endif > + wiphy_unregister(local->hw.wiphy); > + fail_wiphy_register: > rtnl_lock(); > rate_control_deinitialize(local); > ieee80211_remove_interfaces(local); > @@ -1302,8 +1308,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > ieee80211_led_exit(local); > destroy_workqueue(local->workqueue); > fail_workqueue: > - wiphy_unregister(local->hw.wiphy); > - fail_wiphy_register: > if (local->wiphy_ciphers_allocated) > kfree(local->hw.wiphy->cipher_suites); > kfree(local->int_scan_req); > @@ -1353,8 +1357,8 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) > skb_queue_purge(&local->skb_queue_unreliable); > skb_queue_purge(&local->skb_queue_tdls_chsw); > > - destroy_workqueue(local->workqueue); > wiphy_unregister(local->hw.wiphy); > + destroy_workqueue(local->workqueue); > ieee80211_led_exit(local); > kfree(local->int_scan_req); > } > -- > 2.7.4 > -- Thanks, Regards, Chaitanya T K. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] mac80211: fix race in ieee80211_register_hw() 2020-04-07 19:25 ` Krishna Chaitanya @ 2020-04-09 4:42 ` Sumit Garg 2020-04-09 4:44 ` Sedat Dilek 2020-04-15 11:35 ` Sumit Garg 0 siblings, 2 replies; 8+ messages in thread From: Sumit Garg @ 2020-04-09 4:42 UTC (permalink / raw) To: Johannes Berg Cc: linux-wireless, Krishna Chaitanya, David S. Miller, kuba, Kalle Valo, netdev, Linux Kernel Mailing List, Matthias-Peter Schöpfer, Berg Philipp (HAU-EDS), Weitner Michael (HAU-EDS), Daniel Thompson, Loic Poulain, stable Hi Johannes, On Wed, 8 Apr 2020 at 00:55, Krishna Chaitanya <chaitanya.mgit@gmail.com> wrote: > > On Tue, Apr 7, 2020 at 3:41 PM Sumit Garg <sumit.garg@linaro.org> wrote: > > > > A race condition leading to a kernel crash is observed during invocation > > of ieee80211_register_hw() on a dragonboard410c device having wcn36xx > > driver built as a loadable module along with a wifi manager in user-space > > waiting for a wifi device (wlanX) to be active. > > > > Sequence diagram for a particular kernel crash scenario: > > > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > | | | > > |<---phy0----wiphy_register() | > > |-----iwd if_add---->| | > just a nitpick, a better one would be (iwd: if_add + ap_start) since > we need to have 'iwctl ap start' > to trigger the interrupts. > > | |<---IRQ----(RX packet) > > | Kernel crash | > > | due to unallocated | > > | workqueue. | > > | | | > > | alloc_ordered_workqueue() | > > | | | > > | Misc wiphy init. | > > | | | > > | ieee80211_if_add() | > > | | | > > > > As evident from above sequence diagram, this race condition isn't specific > > to a particular wifi driver but rather the initialization sequence in > > ieee80211_register_hw() needs to be fixed. So re-order the initialization > > sequence and the updated sequence diagram would look like: > > > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > | | | > > | alloc_ordered_workqueue() | > > | | | > > | Misc wiphy init. | > > | | | > > |<---phy0----wiphy_register() | > > |-----iwd if_add---->| | > same as above. > > | |<---IRQ----(RX packet) > > | | | > > | ieee80211_if_add() | > > | | | > > > > Cc: <stable@vger.kernel.org> > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org> > > --- > > In case we don't have any further comments, could you fix this nitpick from Chaitanya while applying or would you like me to respin and send v3? -Sumit > > Changes in v2: > > - Move rtnl_unlock() just after ieee80211_init_rate_ctrl_alg(). > > - Update sequence diagrams in commit message for more clarification. > > > > net/mac80211/main.c | 22 +++++++++++++--------- > > 1 file changed, 13 insertions(+), 9 deletions(-) > > > > diff --git a/net/mac80211/main.c b/net/mac80211/main.c > > index 4c2b5ba..d497129 100644 > > --- a/net/mac80211/main.c > > +++ b/net/mac80211/main.c > > @@ -1051,7 +1051,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC; > > if (hw->max_signal <= 0) { > > result = -EINVAL; > > - goto fail_wiphy_register; > > + goto fail_workqueue; > > } > > } > > > > @@ -1113,7 +1113,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > > result = ieee80211_init_cipher_suites(local); > > if (result < 0) > > - goto fail_wiphy_register; > > + goto fail_workqueue; > > > > if (!local->ops->remain_on_channel) > > local->hw.wiphy->max_remain_on_channel_duration = 5000; > > @@ -1139,10 +1139,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > > local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM; > > > > - result = wiphy_register(local->hw.wiphy); > > - if (result < 0) > > - goto fail_wiphy_register; > > - > > /* > > * We use the number of queues for feature tests (QoS, HT) internally > > * so restrict them appropriately. > > @@ -1207,6 +1203,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > goto fail_rate; > > } > > > > + rtnl_unlock(); > > + > > if (local->rate_ctrl) { > > clear_bit(IEEE80211_HW_SUPPORTS_VHT_EXT_NSS_BW, hw->flags); > > if (local->rate_ctrl->ops->capa & RATE_CTRL_CAPA_VHT_EXT_NSS_BW) > > @@ -1254,6 +1252,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > local->sband_allocated |= BIT(band); > > } > > > > + result = wiphy_register(local->hw.wiphy); > > + if (result < 0) > > + goto fail_wiphy_register; > > + > > + rtnl_lock(); > > + > > /* add one default STA interface if supported */ > > if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) && > > !ieee80211_hw_check(hw, NO_AUTO_VIF)) { > > @@ -1293,6 +1297,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > #if defined(CONFIG_INET) || defined(CONFIG_IPV6) > > fail_ifa: > > #endif > > + wiphy_unregister(local->hw.wiphy); > > + fail_wiphy_register: > > rtnl_lock(); > > rate_control_deinitialize(local); > > ieee80211_remove_interfaces(local); > > @@ -1302,8 +1308,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > ieee80211_led_exit(local); > > destroy_workqueue(local->workqueue); > > fail_workqueue: > > - wiphy_unregister(local->hw.wiphy); > > - fail_wiphy_register: > > if (local->wiphy_ciphers_allocated) > > kfree(local->hw.wiphy->cipher_suites); > > kfree(local->int_scan_req); > > @@ -1353,8 +1357,8 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) > > skb_queue_purge(&local->skb_queue_unreliable); > > skb_queue_purge(&local->skb_queue_tdls_chsw); > > > > - destroy_workqueue(local->workqueue); > > wiphy_unregister(local->hw.wiphy); > > + destroy_workqueue(local->workqueue); > > ieee80211_led_exit(local); > > kfree(local->int_scan_req); > > } > > -- > > 2.7.4 > > > > > -- > Thanks, > Regards, > Chaitanya T K. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] mac80211: fix race in ieee80211_register_hw() 2020-04-09 4:42 ` Sumit Garg @ 2020-04-09 4:44 ` Sedat Dilek 2020-04-15 11:35 ` Sumit Garg 1 sibling, 0 replies; 8+ messages in thread From: Sedat Dilek @ 2020-04-09 4:44 UTC (permalink / raw) To: Sumit Garg Cc: Johannes Berg, linux-wireless, Krishna Chaitanya, David S. Miller, kuba, Kalle Valo, netdev, Linux Kernel Mailing List, Matthias-Peter Schöpfer, Berg Philipp (HAU-EDS), Weitner Michael (HAU-EDS), Daniel Thompson, Loic Poulain, stable On Thu, Apr 9, 2020 at 6:43 AM Sumit Garg <sumit.garg@linaro.org> wrote: > > Hi Johannes, > > On Wed, 8 Apr 2020 at 00:55, Krishna Chaitanya <chaitanya.mgit@gmail.com> wrote: > > > > On Tue, Apr 7, 2020 at 3:41 PM Sumit Garg <sumit.garg@linaro.org> wrote: > > > > > > A race condition leading to a kernel crash is observed during invocation > > > of ieee80211_register_hw() on a dragonboard410c device having wcn36xx > > > driver built as a loadable module along with a wifi manager in user-space > > > waiting for a wifi device (wlanX) to be active. > > > > > > Sequence diagram for a particular kernel crash scenario: > > > > > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > | | | > > > |<---phy0----wiphy_register() | > > > |-----iwd if_add---->| | > > just a nitpick, a better one would be (iwd: if_add + ap_start) since > > we need to have 'iwctl ap start' > > to trigger the interrupts. > > > | |<---IRQ----(RX packet) > > > | Kernel crash | > > > | due to unallocated | > > > | workqueue. | > > > | | | > > > | alloc_ordered_workqueue() | > > > | | | > > > | Misc wiphy init. | > > > | | | > > > | ieee80211_if_add() | > > > | | | > > > > > > As evident from above sequence diagram, this race condition isn't specific > > > to a particular wifi driver but rather the initialization sequence in > > > ieee80211_register_hw() needs to be fixed. So re-order the initialization > > > sequence and the updated sequence diagram would look like: > > > > > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > | | | > > > | alloc_ordered_workqueue() | > > > | | | > > > | Misc wiphy init. | > > > | | | > > > |<---phy0----wiphy_register() | > > > |-----iwd if_add---->| | > > same as above. > > > | |<---IRQ----(RX packet) > > > | | | > > > | ieee80211_if_add() | > > > | | | > > > > > > Cc: <stable@vger.kernel.org> > > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org> > > > --- > > > > > In case we don't have any further comments, could you fix this nitpick > from Chaitanya while applying or would you like me to respin and send > v3? > Hi Sumit, when you send out a v3, feel free to add... Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Thanks. Regards, - Sedat - > -Sumit > > > > Changes in v2: > > > - Move rtnl_unlock() just after ieee80211_init_rate_ctrl_alg(). > > > - Update sequence diagrams in commit message for more clarification. > > > > > > net/mac80211/main.c | 22 +++++++++++++--------- > > > 1 file changed, 13 insertions(+), 9 deletions(-) > > > > > > diff --git a/net/mac80211/main.c b/net/mac80211/main.c > > > index 4c2b5ba..d497129 100644 > > > --- a/net/mac80211/main.c > > > +++ b/net/mac80211/main.c > > > @@ -1051,7 +1051,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC; > > > if (hw->max_signal <= 0) { > > > result = -EINVAL; > > > - goto fail_wiphy_register; > > > + goto fail_workqueue; > > > } > > > } > > > > > > @@ -1113,7 +1113,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > > > > result = ieee80211_init_cipher_suites(local); > > > if (result < 0) > > > - goto fail_wiphy_register; > > > + goto fail_workqueue; > > > > > > if (!local->ops->remain_on_channel) > > > local->hw.wiphy->max_remain_on_channel_duration = 5000; > > > @@ -1139,10 +1139,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > > > > local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM; > > > > > > - result = wiphy_register(local->hw.wiphy); > > > - if (result < 0) > > > - goto fail_wiphy_register; > > > - > > > /* > > > * We use the number of queues for feature tests (QoS, HT) internally > > > * so restrict them appropriately. > > > @@ -1207,6 +1203,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > goto fail_rate; > > > } > > > > > > + rtnl_unlock(); > > > + > > > if (local->rate_ctrl) { > > > clear_bit(IEEE80211_HW_SUPPORTS_VHT_EXT_NSS_BW, hw->flags); > > > if (local->rate_ctrl->ops->capa & RATE_CTRL_CAPA_VHT_EXT_NSS_BW) > > > @@ -1254,6 +1252,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > local->sband_allocated |= BIT(band); > > > } > > > > > > + result = wiphy_register(local->hw.wiphy); > > > + if (result < 0) > > > + goto fail_wiphy_register; > > > + > > > + rtnl_lock(); > > > + > > > /* add one default STA interface if supported */ > > > if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) && > > > !ieee80211_hw_check(hw, NO_AUTO_VIF)) { > > > @@ -1293,6 +1297,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > #if defined(CONFIG_INET) || defined(CONFIG_IPV6) > > > fail_ifa: > > > #endif > > > + wiphy_unregister(local->hw.wiphy); > > > + fail_wiphy_register: > > > rtnl_lock(); > > > rate_control_deinitialize(local); > > > ieee80211_remove_interfaces(local); > > > @@ -1302,8 +1308,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > ieee80211_led_exit(local); > > > destroy_workqueue(local->workqueue); > > > fail_workqueue: > > > - wiphy_unregister(local->hw.wiphy); > > > - fail_wiphy_register: > > > if (local->wiphy_ciphers_allocated) > > > kfree(local->hw.wiphy->cipher_suites); > > > kfree(local->int_scan_req); > > > @@ -1353,8 +1357,8 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) > > > skb_queue_purge(&local->skb_queue_unreliable); > > > skb_queue_purge(&local->skb_queue_tdls_chsw); > > > > > > - destroy_workqueue(local->workqueue); > > > wiphy_unregister(local->hw.wiphy); > > > + destroy_workqueue(local->workqueue); > > > ieee80211_led_exit(local); > > > kfree(local->int_scan_req); > > > } > > > -- > > > 2.7.4 > > > > > > > > > -- > > Thanks, > > Regards, > > Chaitanya T K. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] mac80211: fix race in ieee80211_register_hw() 2020-04-09 4:42 ` Sumit Garg 2020-04-09 4:44 ` Sedat Dilek @ 2020-04-15 11:35 ` Sumit Garg 2020-04-15 13:19 ` Sedat Dilek 1 sibling, 1 reply; 8+ messages in thread From: Sumit Garg @ 2020-04-15 11:35 UTC (permalink / raw) To: Johannes Berg Cc: linux-wireless, Krishna Chaitanya, David S. Miller, kuba, Kalle Valo, netdev, Linux Kernel Mailing List, Matthias-Peter Schöpfer, Berg Philipp (HAU-EDS), Weitner Michael (HAU-EDS), Daniel Thompson, Loic Poulain, stable On Thu, 9 Apr 2020 at 10:12, Sumit Garg <sumit.garg@linaro.org> wrote: > > Hi Johannes, > > On Wed, 8 Apr 2020 at 00:55, Krishna Chaitanya <chaitanya.mgit@gmail.com> wrote: > > > > On Tue, Apr 7, 2020 at 3:41 PM Sumit Garg <sumit.garg@linaro.org> wrote: > > > > > > A race condition leading to a kernel crash is observed during invocation > > > of ieee80211_register_hw() on a dragonboard410c device having wcn36xx > > > driver built as a loadable module along with a wifi manager in user-space > > > waiting for a wifi device (wlanX) to be active. > > > > > > Sequence diagram for a particular kernel crash scenario: > > > > > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > | | | > > > |<---phy0----wiphy_register() | > > > |-----iwd if_add---->| | > > just a nitpick, a better one would be (iwd: if_add + ap_start) since > > we need to have 'iwctl ap start' > > to trigger the interrupts. > > > | |<---IRQ----(RX packet) > > > | Kernel crash | > > > | due to unallocated | > > > | workqueue. | > > > | | | > > > | alloc_ordered_workqueue() | > > > | | | > > > | Misc wiphy init. | > > > | | | > > > | ieee80211_if_add() | > > > | | | > > > > > > As evident from above sequence diagram, this race condition isn't specific > > > to a particular wifi driver but rather the initialization sequence in > > > ieee80211_register_hw() needs to be fixed. So re-order the initialization > > > sequence and the updated sequence diagram would look like: > > > > > > user-space ieee80211_register_hw() ieee80211_tasklet_handler() > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > | | | > > > | alloc_ordered_workqueue() | > > > | | | > > > | Misc wiphy init. | > > > | | | > > > |<---phy0----wiphy_register() | > > > |-----iwd if_add---->| | > > same as above. > > > | |<---IRQ----(RX packet) > > > | | | > > > | ieee80211_if_add() | > > > | | | > > > > > > Cc: <stable@vger.kernel.org> > > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org> > > > --- > > > > > In case we don't have any further comments, could you fix this nitpick > from Chaitanya while applying or would you like me to respin and send > v3? A gentle ping. Is this patch a good candidate for 5.7-rc2? -Sumit > > -Sumit > > > > Changes in v2: > > > - Move rtnl_unlock() just after ieee80211_init_rate_ctrl_alg(). > > > - Update sequence diagrams in commit message for more clarification. > > > > > > net/mac80211/main.c | 22 +++++++++++++--------- > > > 1 file changed, 13 insertions(+), 9 deletions(-) > > > > > > diff --git a/net/mac80211/main.c b/net/mac80211/main.c > > > index 4c2b5ba..d497129 100644 > > > --- a/net/mac80211/main.c > > > +++ b/net/mac80211/main.c > > > @@ -1051,7 +1051,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC; > > > if (hw->max_signal <= 0) { > > > result = -EINVAL; > > > - goto fail_wiphy_register; > > > + goto fail_workqueue; > > > } > > > } > > > > > > @@ -1113,7 +1113,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > > > > result = ieee80211_init_cipher_suites(local); > > > if (result < 0) > > > - goto fail_wiphy_register; > > > + goto fail_workqueue; > > > > > > if (!local->ops->remain_on_channel) > > > local->hw.wiphy->max_remain_on_channel_duration = 5000; > > > @@ -1139,10 +1139,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > > > > local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM; > > > > > > - result = wiphy_register(local->hw.wiphy); > > > - if (result < 0) > > > - goto fail_wiphy_register; > > > - > > > /* > > > * We use the number of queues for feature tests (QoS, HT) internally > > > * so restrict them appropriately. > > > @@ -1207,6 +1203,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > goto fail_rate; > > > } > > > > > > + rtnl_unlock(); > > > + > > > if (local->rate_ctrl) { > > > clear_bit(IEEE80211_HW_SUPPORTS_VHT_EXT_NSS_BW, hw->flags); > > > if (local->rate_ctrl->ops->capa & RATE_CTRL_CAPA_VHT_EXT_NSS_BW) > > > @@ -1254,6 +1252,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > local->sband_allocated |= BIT(band); > > > } > > > > > > + result = wiphy_register(local->hw.wiphy); > > > + if (result < 0) > > > + goto fail_wiphy_register; > > > + > > > + rtnl_lock(); > > > + > > > /* add one default STA interface if supported */ > > > if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) && > > > !ieee80211_hw_check(hw, NO_AUTO_VIF)) { > > > @@ -1293,6 +1297,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > #if defined(CONFIG_INET) || defined(CONFIG_IPV6) > > > fail_ifa: > > > #endif > > > + wiphy_unregister(local->hw.wiphy); > > > + fail_wiphy_register: > > > rtnl_lock(); > > > rate_control_deinitialize(local); > > > ieee80211_remove_interfaces(local); > > > @@ -1302,8 +1308,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) > > > ieee80211_led_exit(local); > > > destroy_workqueue(local->workqueue); > > > fail_workqueue: > > > - wiphy_unregister(local->hw.wiphy); > > > - fail_wiphy_register: > > > if (local->wiphy_ciphers_allocated) > > > kfree(local->hw.wiphy->cipher_suites); > > > kfree(local->int_scan_req); > > > @@ -1353,8 +1357,8 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) > > > skb_queue_purge(&local->skb_queue_unreliable); > > > skb_queue_purge(&local->skb_queue_tdls_chsw); > > > > > > - destroy_workqueue(local->workqueue); > > > wiphy_unregister(local->hw.wiphy); > > > + destroy_workqueue(local->workqueue); > > > ieee80211_led_exit(local); > > > kfree(local->int_scan_req); > > > } > > > -- > > > 2.7.4 > > > > > > > > > -- > > Thanks, > > Regards, > > Chaitanya T K. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] mac80211: fix race in ieee80211_register_hw() 2020-04-15 11:35 ` Sumit Garg @ 2020-04-15 13:19 ` Sedat Dilek 2020-04-15 13:39 ` Sumit Garg 0 siblings, 1 reply; 8+ messages in thread From: Sedat Dilek @ 2020-04-15 13:19 UTC (permalink / raw) To: Sumit Garg Cc: Johannes Berg, linux-wireless, Krishna Chaitanya, David S. Miller, kuba, Kalle Valo, netdev, Linux Kernel Mailing List, Matthias-Peter Schöpfer, Berg Philipp (HAU-EDS), Weitner Michael (HAU-EDS), Daniel Thompson, Loic Poulain, stable On Wed, Apr 15, 2020 at 3:10 PM Sumit Garg <sumit.garg@linaro.org> wrote: [.. ] > > In case we don't have any further comments, could you fix this nitpick > > from Chaitanya while applying or would you like me to respin and send > > v3? > > A gentle ping. Is this patch a good candidate for 5.7-rc2? > Hi Sumit, it's in [1] (see [2]) with slightly mods by Johannes but not in Linus tree. Johannes requested a pull-request means will be merged in a next step in net.git and then hopefully land in Linus tree after Dave M. requested a pull-request. Thanks for your patch. Regards, - Sedat - [1] https://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211.git/tag/?h=mac80211-for-net-2020-04-15 [2] https://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211.git/commit/?h=mac80211-for-net-2020-04-15&id=52e04b4ce5d03775b6a78f3ed1097480faacc9fd ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] mac80211: fix race in ieee80211_register_hw() 2020-04-15 13:19 ` Sedat Dilek @ 2020-04-15 13:39 ` Sumit Garg 2020-04-15 13:45 ` Sedat Dilek 0 siblings, 1 reply; 8+ messages in thread From: Sumit Garg @ 2020-04-15 13:39 UTC (permalink / raw) To: sedat.dilek, Johannes Berg Cc: linux-wireless, Krishna Chaitanya, David S. Miller, kuba, Kalle Valo, netdev, Linux Kernel Mailing List, Matthias-Peter Schöpfer, Berg Philipp (HAU-EDS), Weitner Michael (HAU-EDS), Daniel Thompson, Loic Poulain, stable On Wed, 15 Apr 2020 at 18:49, Sedat Dilek <sedat.dilek@gmail.com> wrote: > > On Wed, Apr 15, 2020 at 3:10 PM Sumit Garg <sumit.garg@linaro.org> wrote: > > [.. ] > > > > In case we don't have any further comments, could you fix this nitpick > > > from Chaitanya while applying or would you like me to respin and send > > > v3? > > > > A gentle ping. Is this patch a good candidate for 5.7-rc2? > > > > Hi Sumit, > > it's in [1] (see [2]) with slightly mods by Johannes but not in Linus tree. > Thanks Sedat for this information. > Johannes requested a pull-request means will be merged in a next step > in net.git and then hopefully land in Linus tree after Dave M. > requested a pull-request. I didn't get this PR notification as currently I am not subscribed to linux-wireless ML. So apologies for the noise here. BTW, thanks Johannes for picking up this patch. -Sumit > > Thanks for your patch. > > Regards, > - Sedat - > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211.git/tag/?h=mac80211-for-net-2020-04-15 > [2] https://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211.git/commit/?h=mac80211-for-net-2020-04-15&id=52e04b4ce5d03775b6a78f3ed1097480faacc9fd ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] mac80211: fix race in ieee80211_register_hw() 2020-04-15 13:39 ` Sumit Garg @ 2020-04-15 13:45 ` Sedat Dilek 0 siblings, 0 replies; 8+ messages in thread From: Sedat Dilek @ 2020-04-15 13:45 UTC (permalink / raw) To: Sumit Garg Cc: Johannes Berg, linux-wireless, Krishna Chaitanya, David S. Miller, kuba, Kalle Valo, netdev, Linux Kernel Mailing List, Matthias-Peter Schöpfer, Berg Philipp (HAU-EDS), Weitner Michael (HAU-EDS), Daniel Thompson, Loic Poulain, stable On Wed, Apr 15, 2020 at 3:39 PM Sumit Garg <sumit.garg@linaro.org> wrote: [ ... ] > I didn't get this PR notification as currently I am not subscribed to > linux-wireless ML. So apologies for the noise here. > There is/are a pr-tracker(s) and bots (for example tip tree) around which inform people automatically. But I have never dealt with that topic and thus do not know if there exists something for net/wireless/mac80211 around. - Sedat - ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-04-15 13:46 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-04-07 10:10 [PATCH v2] mac80211: fix race in ieee80211_register_hw() Sumit Garg 2020-04-07 19:25 ` Krishna Chaitanya 2020-04-09 4:42 ` Sumit Garg 2020-04-09 4:44 ` Sedat Dilek 2020-04-15 11:35 ` Sumit Garg 2020-04-15 13:19 ` Sedat Dilek 2020-04-15 13:39 ` Sumit Garg 2020-04-15 13:45 ` Sedat Dilek
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