From 34737e1320db6d51f0d140d5c684b9eb32f0da76 Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Fri, 6 Aug 2021 12:35:09 +0200 Subject: net: wwan: mhi_wwan_ctrl: Fix possible deadlock Lockdep detected possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mhiwwan->rx_lock); local_irq_disable(); lock(&mhi_cntrl->pm_lock); lock(&mhiwwan->rx_lock); lock(&mhi_cntrl->pm_lock); *** DEADLOCK *** To prevent this we need to disable the soft-interrupts when taking the rx_lock. Cc: stable@vger.kernel.org Fixes: fa588eba632d ("net: Add Qcom WWAN control driver") Reported-by: Thomas Perrot Signed-off-by: Loic Poulain Reviewed-by: Sergey Ryazanov Signed-off-by: David S. Miller --- drivers/net/wwan/mhi_wwan_ctrl.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/net/wwan') diff --git a/drivers/net/wwan/mhi_wwan_ctrl.c b/drivers/net/wwan/mhi_wwan_ctrl.c index 1e18420ce404..d0a98f34c54d 100644 --- a/drivers/net/wwan/mhi_wwan_ctrl.c +++ b/drivers/net/wwan/mhi_wwan_ctrl.c @@ -41,14 +41,14 @@ struct mhi_wwan_dev { /* Increment RX budget and schedule RX refill if necessary */ static void mhi_wwan_rx_budget_inc(struct mhi_wwan_dev *mhiwwan) { - spin_lock(&mhiwwan->rx_lock); + spin_lock_bh(&mhiwwan->rx_lock); mhiwwan->rx_budget++; if (test_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags)) schedule_work(&mhiwwan->rx_refill); - spin_unlock(&mhiwwan->rx_lock); + spin_unlock_bh(&mhiwwan->rx_lock); } /* Decrement RX budget if non-zero and return true on success */ @@ -56,7 +56,7 @@ static bool mhi_wwan_rx_budget_dec(struct mhi_wwan_dev *mhiwwan) { bool ret = false; - spin_lock(&mhiwwan->rx_lock); + spin_lock_bh(&mhiwwan->rx_lock); if (mhiwwan->rx_budget) { mhiwwan->rx_budget--; @@ -64,7 +64,7 @@ static bool mhi_wwan_rx_budget_dec(struct mhi_wwan_dev *mhiwwan) ret = true; } - spin_unlock(&mhiwwan->rx_lock); + spin_unlock_bh(&mhiwwan->rx_lock); return ret; } @@ -130,9 +130,9 @@ static void mhi_wwan_ctrl_stop(struct wwan_port *port) { struct mhi_wwan_dev *mhiwwan = wwan_port_get_drvdata(port); - spin_lock(&mhiwwan->rx_lock); + spin_lock_bh(&mhiwwan->rx_lock); clear_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags); - spin_unlock(&mhiwwan->rx_lock); + spin_unlock_bh(&mhiwwan->rx_lock); cancel_work_sync(&mhiwwan->rx_refill); -- cgit v1.2.3 From d9d5b8961284b0051726e0fcda91d1e297e087f5 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 11 Aug 2021 15:48:45 +0300 Subject: wwan: core: Avoid returning NULL from wwan_create_dev() Make wwan_create_dev() to return either valid or error pointer, In some cases it may return NULL. Prevent this by converting it to the respective error pointer. Fixes: 9a44c1cc6388 ("net: Add a WWAN subsystem") Signed-off-by: Andy Shevchenko Acked-by: Sergey Ryazanov Reviewed-by: Loic Poulain Link: https://lore.kernel.org/r/20210811124845.10955-1-andriy.shevchenko@linux.intel.com Signed-off-by: Jakub Kicinski --- drivers/net/wwan/wwan_core.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'drivers/net/wwan') diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index 674a81d79db3..35ece98134c0 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -164,11 +164,14 @@ static struct wwan_device *wwan_create_dev(struct device *parent) goto done_unlock; id = ida_alloc(&wwan_dev_ids, GFP_KERNEL); - if (id < 0) + if (id < 0) { + wwandev = ERR_PTR(id); goto done_unlock; + } wwandev = kzalloc(sizeof(*wwandev), GFP_KERNEL); if (!wwandev) { + wwandev = ERR_PTR(-ENOMEM); ida_free(&wwan_dev_ids, id); goto done_unlock; } @@ -182,7 +185,8 @@ static struct wwan_device *wwan_create_dev(struct device *parent) err = device_register(&wwandev->dev); if (err) { put_device(&wwandev->dev); - wwandev = NULL; + wwandev = ERR_PTR(err); + goto done_unlock; } done_unlock: @@ -1014,8 +1018,8 @@ int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, return -EINVAL; wwandev = wwan_create_dev(parent); - if (!wwandev) - return -ENOMEM; + if (IS_ERR(wwandev)) + return PTR_ERR(wwandev); if (WARN_ON(wwandev->ops)) { wwan_remove_dev(wwandev); -- cgit v1.2.3