The patch titled
unprivileged mounts: allow unprivileged umount
has been removed from the -mm tree. Its filename was
unprivileged-mounts-allow-unprivileged-umount.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
Subject: unprivileged mounts: allow unprivileged umount
From: Miklos Szeredi <mszeredi@xxxxxxx>
The owner doesn't need sysadmin capabilities to call umount().
Similar behavior as umount(8) on mounts having "user=UID" option in /etc/mtab.
The difference is that umount also checks /etc/fstab, presumably to exclude
another mount on the same mountpoint.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Cc: Ram Pai <linuxram@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/namespace.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff -puN fs/namespace.c~unprivileged-mounts-allow-unprivileged-umount fs/namespace.c
--- a/fs/namespace.c~unprivileged-mounts-allow-unprivileged-umount
+++ a/fs/namespace.c
@@ -634,6 +634,27 @@ static int do_umount(struct vfsmount *mn
return retval;
}
+static bool is_mount_owner(struct vfsmount *mnt, uid_t uid)
+{
+ return (mnt->mnt_flags & MNT_USER) && mnt->mnt_uid == uid;
+}
+
+/*
+ * umount is permitted for
+ * - sysadmin
+ * - mount owner, if not forced umount
+ */
+static bool permit_umount(struct vfsmount *mnt, int flags)
+{
+ if (capable(CAP_SYS_ADMIN))
+ return true;
+
+ if (flags & MNT_FORCE)
+ return false;
+
+ return is_mount_owner(mnt, current->fsuid);
+}
+
/*
* Now umount can handle mount points as well as block devices.
* This is important for filesystems which use unnamed block devices.
@@ -657,7 +678,7 @@ asmlinkage long sys_umount(char __user *
goto dput_and_out;
retval = -EPERM;
- if (!capable(CAP_SYS_ADMIN))
+ if (!permit_umount(nd.mnt, flags))
goto dput_and_out;
retval = do_umount(nd.mnt, flags);
_
Patches currently in -mm which might be from mszeredi@xxxxxxx are
fuse-fix-reading-past-eof.patch
fuse-cleanup-add-fuse_get_attr_version.patch
fuse-pass-open-flags-to-read-and-write.patch
fuse-fix-fuse_file_ops-sending.patch
fuse-fix-uninitialized-field-in-fuse_inode.patch
fuse-fix-attribute-caching-after-rename.patch
unprivileged-mounts-allow-unprivileged-umount.patch
unprivileged-mounts-account-user-mounts.patch
unprivileged-mounts-propagate-error-values-from-clone_mnt.patch
unprivileged-mounts-allow-unprivileged-bind-mounts.patch
unprivileged-mounts-allow-unprivileged-mounts.patch
unprivileged-mounts-allow-unprivileged-fuse-mounts.patch
unprivileged-mounts-propagation-inherit-owner-from-parent.patch
unprivileged-mounts-add-no-submounts-flag.patch
slab-api-remove-useless-ctor-parameter-and-reorder-parameters-vs-revoke.patch
fs-introduce-write_begin-write_end-and-perform_write-aops-revoke-fix.patch
-
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