[PATCH v4 16/21] fs: Allow superblock owner to access do_remount_sb()
From: Seth Forshee <hidden>
Date: 2016-04-26 19:36:29
Also in:
cgroups, dm-devel, linux-bcache, linux-fsdevel, lkml, selinux
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
Superblock level remounts are currently restricted to global CAP_SYS_ADMIN, as is the path for changing the root mount to read only on umount. Loosen both of these permission checks to also allow CAP_SYS_ADMIN in any namespace which is privileged towards the userns which originally mounted the filesystem. Signed-off-by: Seth Forshee <redacted> Acked-by: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> Acked-by: Serge Hallyn <redacted> --- fs/namespace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index 0ad8e4a4f50b..575e3f8b34fd 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c@@ -1510,7 +1510,7 @@ static int do_umount(struct mount *mnt, int flags) * Special case for "unmounting" root ... * we just try to remount it readonly. */ - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) return -EPERM; down_write(&sb->s_umount); if (!(sb->s_flags & MS_RDONLY))
@@ -2207,7 +2207,7 @@ static int do_remount(struct path *path, int flags, int mnt_flags, down_write(&sb->s_umount); if (flags & MS_BIND) err = change_mount_flags(path->mnt, flags); - else if (!capable(CAP_SYS_ADMIN)) + else if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) err = -EPERM; else err = do_remount_sb(sb, flags, data, 0);
--
2.7.4
------------------------------------------------------------------------------
Find and fix application performance issues faster with Applications Manager
Applications Manager provides deep performance insights into multiple tiers of
your business applications. It resolves application problems quickly and
reduces your MTTR. Get your free trial!
https://ad.doubleclick.net/ddm/clk/302982198;130105516;z
--
fuse-devel mailing list
To unsubscribe or subscribe, visit https://lists.sourceforge.net/lists/listinfo/fuse-devel