2021-01-21 13:26:41

by Christian Brauner

Subject: [PATCH v6 19/40] fcntl: handle idmapped mounts

Enable the setfl() helper to handle idmapped mounts by passing down the
mount's user namespace. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/[email protected]
Cc: Christoph Hellwig <[email protected]>
Cc: David Howells <[email protected]>
Cc: Al Viro <[email protected]>
Cc: [email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>
---
/* v2 */
patch introduced

/* v3 */
unchanged

/* v4 */
unchanged

/* v5 */
unchanged
base-commit: 7c53f6b671f4aba70ff15e1b05148b10d58c2837

/* v6 */
base-commit: 19c329f6808995b142b3966301f217c831e7cf31

- Christoph Hellwig <[email protected]>:
- Use file_mnt_user_ns() helper.
---
fs/fcntl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 74d99731fd43..f6ac5285060d 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -25,6 +25,7 @@
#include <linux/user_namespace.h>
#include <linux/memfd.h>
#include <linux/compat.h>
+#include <linux/mount.h>

#include <linux/poll.h>
#include <asm/siginfo.h>
@@ -46,7 +47,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg)

/* O_NOATIME can only be set by the owner or superuser */
if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
- if (!inode_owner_or_capable(&init_user_ns, inode))
+ if (!inode_owner_or_capable(file_mnt_user_ns(filp), inode))
return -EPERM;

/* required for strict SunOS emulation */
--
2.30.0

2021-01-22 04:19:42

by James Morris

Subject: Re: [PATCH v6 19/40] fcntl: handle idmapped mounts

On Thu, 21 Jan 2021, Christian Brauner wrote:

> Enable the setfl() helper to handle idmapped mounts by passing down the
> mount's user namespace. If the initial user namespace is passed nothing
> changes so non-idmapped mounts will see identical behavior as before.
>
> Link: https://lore.kernel.org/r/[email protected]
> Cc: Christoph Hellwig <[email protected]>
> Cc: David Howells <[email protected]>
> Cc: Al Viro <[email protected]>
> Cc: [email protected]
> Reviewed-by: Christoph Hellwig <[email protected]>
> Signed-off-by: Christian Brauner <[email protected]>


Reviewed-by: James Morris <[email protected]>


--
James Morris
<[email protected]>