From: Pan Bian Date: Wed, 17 Apr 2019 08:28:37 +0000 (+0800) Subject: mmc: core: fix possible use after free of host X-Git-Tag: v5.15~6453^2~27 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8e1943af2986db42bee2b8dddf49a36cdb2e9219;p=platform%2Fkernel%2Flinux-starfive.git mmc: core: fix possible use after free of host In the function mmc_alloc_host, the function put_device is called to release allocated resources when mmc_gpio_alloc fails. Finally, the function pointed by host->class_dev.class->dev_release (i.e., mmc_host_classdev_release) is used to release resources including the host structure. However, after put_device, host is used and released again. Resulting in a use-after-free bug. Fixes: 1ed217194488 ("mmc: core: fix error path in mmc_host_alloc") Signed-off-by: Pan Bian Signed-off-by: Ulf Hansson --- diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index b3fa9c9..6a51f7a 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -429,8 +429,6 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev) if (mmc_gpio_alloc(host)) { put_device(&host->class_dev); - ida_simple_remove(&mmc_host_ida, host->index); - kfree(host); return NULL; }