There is an issue in brcmfmac clean-up during USB disconnect which may lead to
usb_hub_wq lock-up and possible memory corruption. With this series fix the
race causing the issue and also do minor clean-up of brcmf_usb_free_q.
Piotr Figiel (3):
brcmfmac: fix race during disconnect when USB completion is in
progress
brcmfmac: remove pending parameter from brcmf_usb_free_q
brcmfmac: remove unused variable i from brcmf_usb_free_q
.../net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 27 +++++++++++-----------
1 file changed, 14 insertions(+), 13 deletions(-)
--
2.7.4
It was observed that rarely during USB disconnect happening shortly after
connect (before full initialization completes) usb_hub_wq would wait
forever for the dev_init_lock to be unlocked. dev_init_lock would remain
locked though because of infinite wait during usb_kill_urb:
[ 2730.656472] kworker/0:2 D 0 260 2 0x00000000
[ 2730.660700] Workqueue: events request_firmware_work_func
[ 2730.664807] [<809dca20>] (__schedule) from [<809dd164>] (schedule+0x4c/0xac)
[ 2730.670587] [<809dd164>] (schedule) from [<8069af44>] (usb_kill_urb+0xdc/0x114)
[ 2730.676815] [<8069af44>] (usb_kill_urb) from [<7f258b50>] (brcmf_usb_free_q+0x34/0xa8 [brcmfmac])
[ 2730.684833] [<7f258b50>] (brcmf_usb_free_q [brcmfmac]) from [<7f2517d4>] (brcmf_detach+0xa0/0xb8 [brcmfmac])
[ 2730.693557] [<7f2517d4>] (brcmf_detach [brcmfmac]) from [<7f251a34>] (brcmf_attach+0xac/0x3d8 [brcmfmac])
[ 2730.702094] [<7f251a34>] (brcmf_attach [brcmfmac]) from [<7f2587ac>] (brcmf_usb_probe_phase2+0x468/0x4a0 [brcmfmac])
[ 2730.711601] [<7f2587ac>] (brcmf_usb_probe_phase2 [brcmfmac]) from [<7f252888>] (brcmf_fw_request_done+0x194/0x220 [brcmfmac])
[ 2730.721795] [<7f252888>] (brcmf_fw_request_done [brcmfmac]) from [<805748e4>] (request_firmware_work_func+0x4c/0x88)
[ 2730.731125] [<805748e4>] (request_firmware_work_func) from [<80141474>] (process_one_work+0x228/0x808)
[ 2730.739223] [<80141474>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564)
[ 2730.746105] [<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c)
[ 2730.752227] [<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20)
[ 2733.099695] kworker/0:3 D 0 1065 2 0x00000000
[ 2733.103926] Workqueue: usb_hub_wq hub_event
[ 2733.106914] [<809dca20>] (__schedule) from [<809dd164>] (schedule+0x4c/0xac)
[ 2733.112693] [<809dd164>] (schedule) from [<809e2a8c>] (schedule_timeout+0x214/0x3e4)
[ 2733.119621] [<809e2a8c>] (schedule_timeout) from [<809dde2c>] (wait_for_common+0xc4/0x1c0)
[ 2733.126810] [<809dde2c>] (wait_for_common) from [<7f258d00>] (brcmf_usb_disconnect+0x1c/0x4c [brcmfmac])
[ 2733.135206] [<7f258d00>] (brcmf_usb_disconnect [brcmfmac]) from [<8069e0c8>] (usb_unbind_interface+0x5c/0x1e4)
[ 2733.143943] [<8069e0c8>] (usb_unbind_interface) from [<8056d3e8>] (device_release_driver_internal+0x164/0x1fc)
[ 2733.152769] [<8056d3e8>] (device_release_driver_internal) from [<8056c078>] (bus_remove_device+0xd0/0xfc)
[ 2733.161138] [<8056c078>] (bus_remove_device) from [<8056977c>] (device_del+0x11c/0x310)
[ 2733.167939] [<8056977c>] (device_del) from [<8069cba8>] (usb_disable_device+0xa0/0x1cc)
[ 2733.174743] [<8069cba8>] (usb_disable_device) from [<8069507c>] (usb_disconnect+0x74/0x1dc)
[ 2733.181823] [<8069507c>] (usb_disconnect) from [<80695e88>] (hub_event+0x478/0xf88)
[ 2733.188278] [<80695e88>] (hub_event) from [<80141474>] (process_one_work+0x228/0x808)
[ 2733.194905] [<80141474>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564)
[ 2733.201724] [<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c)
[ 2733.207913] [<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20)
It was traced down to a case where usb_kill_urb would be called on an URB
structure containing more or less random data, including large number in
its use_count. During the debugging it appeared that in brcmf_usb_free_q()
the traversal over URBs' lists is not synchronized with operations on those
lists in brcmf_usb_rx_complete() leading to handling
brcmf_usbdev_info structure (holding lists' head) as lists' element and in
result causing above problem.
Fix it by walking through all URBs during brcmf_cancel_all_urbs using the
arrays of requests instead of linked lists.
Signed-off-by: Piotr Figiel <[email protected]>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index e9cbfd0..a775409 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -682,12 +682,18 @@ static int brcmf_usb_up(struct device *dev)
static void brcmf_cancel_all_urbs(struct brcmf_usbdev_info *devinfo)
{
+ int i;
+
if (devinfo->ctl_urb)
usb_kill_urb(devinfo->ctl_urb);
if (devinfo->bulk_urb)
usb_kill_urb(devinfo->bulk_urb);
- brcmf_usb_free_q(&devinfo->tx_postq, true);
- brcmf_usb_free_q(&devinfo->rx_postq, true);
+ if (devinfo->tx_reqs)
+ for (i = 0; i < devinfo->bus_pub.ntxq; i++)
+ usb_kill_urb(devinfo->tx_reqs[i].urb);
+ if (devinfo->rx_reqs)
+ for (i = 0; i < devinfo->bus_pub.nrxq; i++)
+ usb_kill_urb(devinfo->rx_reqs[i].urb);
}
static void brcmf_usb_down(struct device *dev)
--
2.7.4
Variable i is not used so remove it.
Signed-off-by: Piotr Figiel <[email protected]>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index 5ab397d..c00b9fd 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -449,13 +449,11 @@ static void brcmf_usb_free_q(struct list_head *q)
{
struct brcmf_usbreq *req, *next;
- int i = 0;
list_for_each_entry_safe(req, next, q, list) {
if (!req->urb) {
brcmf_err("bad req\n");
break;
}
- i++;
usb_free_urb(req->urb);
list_del_init(&req->list);
}
--
2.7.4
brcmf_usb_free_q is no longer called with pending=true thus this boolean
parameter is no longer needed.
Signed-off-by: Piotr Figiel <[email protected]>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index a775409..5ab397d 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -445,9 +445,10 @@ brcmf_usbdev_qinit(struct list_head *q, int qsize)
}
-static void brcmf_usb_free_q(struct list_head *q, bool pending)
+static void brcmf_usb_free_q(struct list_head *q)
{
struct brcmf_usbreq *req, *next;
+
int i = 0;
list_for_each_entry_safe(req, next, q, list) {
if (!req->urb) {
@@ -455,12 +456,8 @@ static void brcmf_usb_free_q(struct list_head *q, bool pending)
break;
}
i++;
- if (pending) {
- usb_kill_urb(req->urb);
- } else {
- usb_free_urb(req->urb);
- list_del_init(&req->list);
- }
+ usb_free_urb(req->urb);
+ list_del_init(&req->list);
}
}
@@ -1029,8 +1026,8 @@ static void brcmf_usb_detach(struct brcmf_usbdev_info *devinfo)
brcmf_dbg(USB, "Enter, devinfo %p\n", devinfo);
/* free the URBS */
- brcmf_usb_free_q(&devinfo->rx_freeq, false);
- brcmf_usb_free_q(&devinfo->tx_freeq, false);
+ brcmf_usb_free_q(&devinfo->rx_freeq);
+ brcmf_usb_free_q(&devinfo->tx_freeq);
usb_free_urb(devinfo->ctl_urb);
usb_free_urb(devinfo->bulk_urb);
--
2.7.4
Piotr Figiel <[email protected]> wrote:
> It was observed that rarely during USB disconnect happening shortly after
> connect (before full initialization completes) usb_hub_wq would wait
> forever for the dev_init_lock to be unlocked. dev_init_lock would remain
> locked though because of infinite wait during usb_kill_urb:
>
> [ 2730.656472] kworker/0:2 D 0 260 2 0x00000000
> [ 2730.660700] Workqueue: events request_firmware_work_func
> [ 2730.664807] [<809dca20>] (__schedule) from [<809dd164>] (schedule+0x4c/0xac)
> [ 2730.670587] [<809dd164>] (schedule) from [<8069af44>] (usb_kill_urb+0xdc/0x114)
> [ 2730.676815] [<8069af44>] (usb_kill_urb) from [<7f258b50>] (brcmf_usb_free_q+0x34/0xa8 [brcmfmac])
> [ 2730.684833] [<7f258b50>] (brcmf_usb_free_q [brcmfmac]) from [<7f2517d4>] (brcmf_detach+0xa0/0xb8 [brcmfmac])
> [ 2730.693557] [<7f2517d4>] (brcmf_detach [brcmfmac]) from [<7f251a34>] (brcmf_attach+0xac/0x3d8 [brcmfmac])
> [ 2730.702094] [<7f251a34>] (brcmf_attach [brcmfmac]) from [<7f2587ac>] (brcmf_usb_probe_phase2+0x468/0x4a0 [brcmfmac])
> [ 2730.711601] [<7f2587ac>] (brcmf_usb_probe_phase2 [brcmfmac]) from [<7f252888>] (brcmf_fw_request_done+0x194/0x220 [brcmfmac])
> [ 2730.721795] [<7f252888>] (brcmf_fw_request_done [brcmfmac]) from [<805748e4>] (request_firmware_work_func+0x4c/0x88)
> [ 2730.731125] [<805748e4>] (request_firmware_work_func) from [<80141474>] (process_one_work+0x228/0x808)
> [ 2730.739223] [<80141474>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564)
> [ 2730.746105] [<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c)
> [ 2730.752227] [<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20)
>
> [ 2733.099695] kworker/0:3 D 0 1065 2 0x00000000
> [ 2733.103926] Workqueue: usb_hub_wq hub_event
> [ 2733.106914] [<809dca20>] (__schedule) from [<809dd164>] (schedule+0x4c/0xac)
> [ 2733.112693] [<809dd164>] (schedule) from [<809e2a8c>] (schedule_timeout+0x214/0x3e4)
> [ 2733.119621] [<809e2a8c>] (schedule_timeout) from [<809dde2c>] (wait_for_common+0xc4/0x1c0)
> [ 2733.126810] [<809dde2c>] (wait_for_common) from [<7f258d00>] (brcmf_usb_disconnect+0x1c/0x4c [brcmfmac])
> [ 2733.135206] [<7f258d00>] (brcmf_usb_disconnect [brcmfmac]) from [<8069e0c8>] (usb_unbind_interface+0x5c/0x1e4)
> [ 2733.143943] [<8069e0c8>] (usb_unbind_interface) from [<8056d3e8>] (device_release_driver_internal+0x164/0x1fc)
> [ 2733.152769] [<8056d3e8>] (device_release_driver_internal) from [<8056c078>] (bus_remove_device+0xd0/0xfc)
> [ 2733.161138] [<8056c078>] (bus_remove_device) from [<8056977c>] (device_del+0x11c/0x310)
> [ 2733.167939] [<8056977c>] (device_del) from [<8069cba8>] (usb_disable_device+0xa0/0x1cc)
> [ 2733.174743] [<8069cba8>] (usb_disable_device) from [<8069507c>] (usb_disconnect+0x74/0x1dc)
> [ 2733.181823] [<8069507c>] (usb_disconnect) from [<80695e88>] (hub_event+0x478/0xf88)
> [ 2733.188278] [<80695e88>] (hub_event) from [<80141474>] (process_one_work+0x228/0x808)
> [ 2733.194905] [<80141474>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564)
> [ 2733.201724] [<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c)
> [ 2733.207913] [<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20)
>
> It was traced down to a case where usb_kill_urb would be called on an URB
> structure containing more or less random data, including large number in
> its use_count. During the debugging it appeared that in brcmf_usb_free_q()
> the traversal over URBs' lists is not synchronized with operations on those
> lists in brcmf_usb_rx_complete() leading to handling
> brcmf_usbdev_info structure (holding lists' head) as lists' element and in
> result causing above problem.
>
> Fix it by walking through all URBs during brcmf_cancel_all_urbs using the
> arrays of requests instead of linked lists.
>
> Signed-off-by: Piotr Figiel <[email protected]>
3 patches applied to wireless-drivers-next.git, thanks.
db3b9e2e1d58 brcmfmac: fix race during disconnect when USB completion is in progress
2b78e5f52236 brcmfmac: remove pending parameter from brcmf_usb_free_q
504f06725d01 brcmfmac: remove unused variable i from brcmf_usb_free_q
--
https://patchwork.kernel.org/patch/10845051/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches