This is a note to let you know that I've just added the patch titled net: fec: Fix reference count leak in fec series ops to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-fec-fix-reference-count-leak-in-fec-series-ops.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sun Nov 22 10:24:40 AM CET 2020 From: Zhang Qilong <zhangqilong3@xxxxxxxxxx> Date: Tue, 10 Nov 2020 17:29:33 +0800 Subject: net: fec: Fix reference count leak in fec series ops From: Zhang Qilong <zhangqilong3@xxxxxxxxxx> [ Upstream commit da875fa5040b0f951cb4bf7efbf59f6dcff44d3c ] pm_runtime_get_sync() will increment pm usage at first and it will resume the device later. If runtime of the device has error or device is in inaccessible state(or other error state), resume operation will fail. If we do not call put operation to decrease the reference, it will result in reference count leak. Moreover, this device cannot enter the idle state and always stay busy or other non-idle state later. So we fixed it by replacing it with pm_runtime_resume_and_get. Fixes: 8fff755e9f8d0 ("net: fec: Ensure clocks are enabled while using mdio bus") Signed-off-by: Zhang Qilong <zhangqilong3@xxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/freescale/fec_main.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1808,7 +1808,7 @@ static int fec_enet_mdio_read(struct mii int ret = 0, frame_start, frame_addr, frame_op; bool is_c45 = !!(regnum & MII_ADDR_C45); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) return ret; @@ -1867,11 +1867,9 @@ static int fec_enet_mdio_write(struct mi int ret, frame_start, frame_addr; bool is_c45 = !!(regnum & MII_ADDR_C45); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) return ret; - else - ret = 0; if (is_c45) { frame_start = FEC_MMFR_ST_C45; @@ -2276,7 +2274,7 @@ static void fec_enet_get_regs(struct net u32 i, off; int ret; - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) return; @@ -2977,7 +2975,7 @@ fec_enet_open(struct net_device *ndev) int ret; bool reset_again; - ret = pm_runtime_get_sync(&fep->pdev->dev); + ret = pm_runtime_resume_and_get(&fep->pdev->dev); if (ret < 0) return ret; @@ -3771,7 +3769,7 @@ fec_drv_remove(struct platform_device *p struct device_node *np = pdev->dev.of_node; int ret; - ret = pm_runtime_get_sync(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); if (ret < 0) return ret; Patches currently in stable-queue which might be from zhangqilong3@xxxxxxxxxx are queue-5.9/ipv6-fix-error-path-to-cancel-the-meseage.patch queue-5.9/net-fec-fix-reference-count-leak-in-fec-series-ops.patch queue-5.9/pm-runtime-add-pm_runtime_resume_and_get-to-deal-with-usage-counter.patch