| Message ID | 1555489717-28294-1-git-send-email-bianpan2016@163.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: core: fix possible use after free of host | expand |
On Wed, Apr 17, 2019 at 10:28 AM Pan Bian <bianpan2016@163.com> wrote: > > 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: 1ed21719448("mmc: core: fix error path in mmc_host_alloc") The original commit 1ed21719448 looks correct to me (see mmc_host_classdev_release). > Signed-off-by: Pan Bian <bianpan2016@163.com> > --- > drivers/mmc/core/host.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index 3a4402a..f8ac567 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; > } > > -- > 2.7.4 > >
On Wed, 17 Apr 2019 at 10:29, Pan Bian <bianpan2016@163.com> wrote: > > 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: 1ed21719448("mmc: core: fix error path in mmc_host_alloc") > Signed-off-by: Pan Bian <bianpan2016@163.com> Applied for next, thanks! Kind regards Uffe > --- > drivers/mmc/core/host.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index 3a4402a..f8ac567 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; > } > > -- > 2.7.4 > >
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index 3a4402a..f8ac567 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; }
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: 1ed21719448("mmc: core: fix error path in mmc_host_alloc") Signed-off-by: Pan Bian <bianpan2016@163.com> --- drivers/mmc/core/host.c | 2 -- 1 file changed, 2 deletions(-)