diff options
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/base/devtmpfs.c | 10 |
2 files changed, 19 insertions, 2 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index ffcbe2bc460e..6f04b831a5c0 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -62,6 +62,17 @@ config DEVTMPFS_MOUNT rescue mode with init=/bin/sh, even when the /dev directory on the rootfs is completely empty. +config DEVTMPFS_SAFE + bool "Use nosuid,noexec mount options on devtmpfs" + depends on DEVTMPFS + help + This instructs the kernel to include the MS_NOEXEC and MS_NOSUID mount + flags when mounting devtmpfs. + + Notice: If enabled, things like /dev/mem cannot be mmapped + with the PROT_EXEC flag. This can break, for example, non-KMS + video drivers. + config STANDALONE bool "Select only drivers that don't need compile-time external firmware" default y diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index 8be352ab4ddb..1e2c2d3882e2 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -29,6 +29,12 @@ #include <uapi/linux/mount.h> #include "base.h" +#ifdef CONFIG_DEVTMPFS_SAFE +#define DEVTMPFS_MFLAGS (MS_SILENT | MS_NOEXEC | MS_NOSUID) +#else +#define DEVTMPFS_MFLAGS (MS_SILENT) +#endif + static struct task_struct *thread; static int __initdata mount_dev = IS_ENABLED(CONFIG_DEVTMPFS_MOUNT); @@ -363,7 +369,7 @@ int __init devtmpfs_mount(void) if (!thread) return 0; - err = init_mount("devtmpfs", "dev", "devtmpfs", MS_SILENT, NULL); + err = init_mount("devtmpfs", "dev", "devtmpfs", DEVTMPFS_MFLAGS, NULL); if (err) printk(KERN_INFO "devtmpfs: error mounting %i\n", err); else @@ -412,7 +418,7 @@ static noinline int __init devtmpfs_setup(void *p) err = ksys_unshare(CLONE_NEWNS); if (err) goto out; - err = init_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL); + err = init_mount("devtmpfs", "/", "devtmpfs", DEVTMPFS_MFLAGS, NULL); if (err) goto out; init_chdir("/.."); /* will traverse into overmounted root */ |