From 4bddd6b38387b664a277dd96066a7ea60cb75072 Mon Sep 17 00:00:00 2001 From: Vladimir Zapolskiy Date: Mon, 23 May 2022 21:17:27 +0800 Subject: [PATCH] i2c: qcom-cci: don't put a device tree node before i2c_add_adapter() stable inclusion from stable-v5.10.102 commit e3fdbc40b7501f3822327d83e039e71d107117ff bugzilla: https://gitee.com/openeuler/kernel/issues/I567K6 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e3fdbc40b7501f3822327d83e039e71d107117ff -------------------------------- commit 02a4a69667a2ad32f3b52ca906f19628fbdd8a01 upstream. There is a minor chance for a race, if a pointer to an i2c-bus subnode is stored and then reused after releasing its reference, and it would be sufficient to get one more reference under a loop over children subnodes. Fixes: e517526195de ("i2c: Add Qualcomm CCI I2C driver") Signed-off-by: Vladimir Zapolskiy Reviewed-by: Robert Foss Reviewed-by: Bjorn Andersson Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yu Liao Reviewed-by: Wei Li Signed-off-by: Zheng Zengkai --- drivers/i2c/busses/i2c-qcom-cci.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c index e5b4c5b724b2..09e599069a81 100644 --- a/drivers/i2c/busses/i2c-qcom-cci.c +++ b/drivers/i2c/busses/i2c-qcom-cci.c @@ -558,7 +558,7 @@ static int cci_probe(struct platform_device *pdev) cci->master[idx].adap.quirks = &cci->data->quirks; cci->master[idx].adap.algo = &cci_algo; cci->master[idx].adap.dev.parent = dev; - cci->master[idx].adap.dev.of_node = child; + cci->master[idx].adap.dev.of_node = of_node_get(child); cci->master[idx].master = idx; cci->master[idx].cci = cci; @@ -643,8 +643,10 @@ static int cci_probe(struct platform_device *pdev) continue; ret = i2c_add_adapter(&cci->master[i].adap); - if (ret < 0) + if (ret < 0) { + of_node_put(cci->master[i].adap.dev.of_node); goto error_i2c; + } } pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC); @@ -656,8 +658,10 @@ static int cci_probe(struct platform_device *pdev) error_i2c: for (--i ; i >= 0; i--) { - if (cci->master[i].cci) + if (cci->master[i].cci) { i2c_del_adapter(&cci->master[i].adap); + of_node_put(cci->master[i].adap.dev.of_node); + } } error: disable_irq(cci->irq); @@ -673,8 +677,10 @@ static int cci_remove(struct platform_device *pdev) int i; for (i = 0; i < cci->data->num_masters; i++) { - if (cci->master[i].cci) + if (cci->master[i].cci) { i2c_del_adapter(&cci->master[i].adap); + of_node_put(cci->master[i].adap.dev.of_node); + } cci_halt(cci, i); } -- GitLab