diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2016-06-09 15:34:02 -0500 |
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committer | Eric W. Biederman <ebiederm@xmission.com> | 2016-06-23 15:41:57 -0500 |
commit | a2982cc922c3068783eb9a1f77a5626a1ec36a1f (patch) | |
tree | 61ccc6ad01f8804d5290ae4565ba8d4238bf648a /fs/kernfs | |
parent | 3ee690143c3c99f6c0e83f08ff17556890bc6027 (diff) | |
download | lwn-a2982cc922c3068783eb9a1f77a5626a1ec36a1f.tar.gz lwn-a2982cc922c3068783eb9a1f77a5626a1ec36a1f.zip |
vfs: Generalize filesystem nodev handling.
Introduce a function may_open_dev that tests MNT_NODEV and a new
superblock flab SB_I_NODEV. Use this new function in all of the
places where MNT_NODEV was previously tested.
Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those
filesystems should never support device nodes, and a simple superblock
flags makes that very hard to get wrong. With SB_I_NODEV set if any
device nodes somehow manage to show up on on a filesystem those
device nodes will be unopenable.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs/kernfs')
-rw-r--r-- | fs/kernfs/mount.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 1443df670260..b3d73ad52b22 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -152,8 +152,8 @@ static int kernfs_fill_super(struct super_block *sb, unsigned long magic) struct dentry *root; info->sb = sb; - /* Userspace would break if executables appear on sysfs */ - sb->s_iflags |= SB_I_NOEXEC; + /* Userspace would break if executables or devices appear on sysfs */ + sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV; sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; sb->s_magic = magic; |