Message ID | 20200422145437.176057-8-christian.brauner@ubuntu.com |
---|---|
State | Not Applicable |
Delegated to: | David Miller |
Headers | show |
Series | loopfs | expand |
On Wed, Apr 22, 2020 at 04:54:37PM +0200, Christian Brauner wrote: > Since loopfs devices belong to a loopfs instance they have no business > polluting the host's devtmpfs mount and should not propagate out of the > namespace they belong to. > > Cc: Jens Axboe <axboe@kernel.dk> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> > --- > /* v2 */ > unchanged > --- > drivers/base/devtmpfs.c | 4 ++-- > drivers/block/loop.c | 4 +++- > include/linux/device.h | 3 +++ > 3 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c > index c9017e0584c0..77371ceb88fa 100644 > --- a/drivers/base/devtmpfs.c > +++ b/drivers/base/devtmpfs.c > @@ -111,7 +111,7 @@ int devtmpfs_create_node(struct device *dev) > const char *tmp = NULL; > struct req req; > > - if (!thread) > + if (!thread || dev->no_devnode) > return 0; > > req.mode = 0; > @@ -138,7 +138,7 @@ int devtmpfs_delete_node(struct device *dev) > const char *tmp = NULL; > struct req req; > > - if (!thread) > + if (!thread || dev->no_devnode) > return 0; > > req.name = device_get_devnode(dev, NULL, NULL, NULL, &tmp); > diff --git a/drivers/block/loop.c b/drivers/block/loop.c > index 2dc53bad4b48..5548151b9f11 100644 > --- a/drivers/block/loop.c > +++ b/drivers/block/loop.c > @@ -2213,8 +2213,10 @@ static int loop_add(struct loop_device **l, int i, struct inode *inode) > disk->queue = lo->lo_queue; > sprintf(disk->disk_name, "loop%d", i); > #ifdef CONFIG_BLK_DEV_LOOPFS > - if (loopfs_i_sb(inode)) > + if (loopfs_i_sb(inode)) { > disk->user_ns = loopfs_i_sb(inode)->s_user_ns; > + disk_to_dev(disk)->no_devnode = true; > + } > #endif > > add_disk(disk); > diff --git a/include/linux/device.h b/include/linux/device.h > index ac8e37cd716a..c69ef1c5a0ef 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -523,6 +523,8 @@ struct dev_links_info { > * sync_state() callback. > * @dma_coherent: this particular device is dma coherent, even if the > * architecture supports non-coherent devices. > + * @no_devnode: whether device nodes associated with this device are kept out > + * of devtmpfs (e.g. due to separate filesystem) > * > * At the lowest level, every device in a Linux system is represented by an > * instance of struct device. The device structure contains the information > @@ -622,6 +624,7 @@ struct device { > defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) > bool dma_coherent:1; > #endif > + bool no_devnode:1; > }; > > static inline struct device *kobj_to_dev(struct kobject *kobj) > -- > 2.26.1
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index c9017e0584c0..77371ceb88fa 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -111,7 +111,7 @@ int devtmpfs_create_node(struct device *dev) const char *tmp = NULL; struct req req; - if (!thread) + if (!thread || dev->no_devnode) return 0; req.mode = 0; @@ -138,7 +138,7 @@ int devtmpfs_delete_node(struct device *dev) const char *tmp = NULL; struct req req; - if (!thread) + if (!thread || dev->no_devnode) return 0; req.name = device_get_devnode(dev, NULL, NULL, NULL, &tmp); diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 2dc53bad4b48..5548151b9f11 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2213,8 +2213,10 @@ static int loop_add(struct loop_device **l, int i, struct inode *inode) disk->queue = lo->lo_queue; sprintf(disk->disk_name, "loop%d", i); #ifdef CONFIG_BLK_DEV_LOOPFS - if (loopfs_i_sb(inode)) + if (loopfs_i_sb(inode)) { disk->user_ns = loopfs_i_sb(inode)->s_user_ns; + disk_to_dev(disk)->no_devnode = true; + } #endif add_disk(disk); diff --git a/include/linux/device.h b/include/linux/device.h index ac8e37cd716a..c69ef1c5a0ef 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -523,6 +523,8 @@ struct dev_links_info { * sync_state() callback. * @dma_coherent: this particular device is dma coherent, even if the * architecture supports non-coherent devices. + * @no_devnode: whether device nodes associated with this device are kept out + * of devtmpfs (e.g. due to separate filesystem) * * At the lowest level, every device in a Linux system is represented by an * instance of struct device. The device structure contains the information @@ -622,6 +624,7 @@ struct device { defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) bool dma_coherent:1; #endif + bool no_devnode:1; }; static inline struct device *kobj_to_dev(struct kobject *kobj)
Since loopfs devices belong to a loopfs instance they have no business polluting the host's devtmpfs mount and should not propagate out of the namespace they belong to. Cc: Jens Axboe <axboe@kernel.dk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> --- /* v2 */ unchanged --- drivers/base/devtmpfs.c | 4 ++-- drivers/block/loop.c | 4 +++- include/linux/device.h | 3 +++ 3 files changed, 8 insertions(+), 3 deletions(-)