Messages in this thread Patch in this message | | | From | Qinglang Miao <> | Subject | [PATCH] s390: cmf: fix use-after-free in enable_cmf | Date | Fri, 20 Nov 2020 15:48:50 +0800 |
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kfree(cdev) is called in put_device in the error branch. So that device_unlock(&cdev->dev) would raise a use-after-free bug. In fact, there's no need to call device_unlock after put_device.
Fix it by adding simply return after put_device.
Fixes: a6ef15652d26 ("s390/cio: fix use after free in cmb processing") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> --- drivers/s390/cio/cmf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/s390/cio/cmf.c b/drivers/s390/cio/cmf.c index 72dd2471e..e95ca476f 100644 --- a/drivers/s390/cio/cmf.c +++ b/drivers/s390/cio/cmf.c @@ -1149,9 +1149,12 @@ int enable_cmf(struct ccw_device *cdev) sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group); cmbops->free(cdev); } + out: - if (ret) + if (ret) { put_device(&cdev->dev); + return ret; + } out_unlock: device_unlock(&cdev->dev); return ret; -- 2.23.0
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