This is a note to let you know that I've just added the patch titled
fs: tweak fsuidgid_has_mapping()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-tweak-fsuidgid_has_mapping.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Jun 30 01:35:30 PM CEST 2022
From: Christian Brauner <brauner@xxxxxxxxxx>
Date: Tue, 28 Jun 2022 14:16:11 +0200
Subject: fs: tweak fsuidgid_has_mapping()
To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <christian.brauner@xxxxxxxxxx>, stable@xxxxxxxxxxxxxxx
Message-ID: <20220628121620.188722-4-brauner@xxxxxxxxxx>
From: Christian Brauner <christian.brauner@xxxxxxxxxx>
commit 476860b3eb4a50958243158861d5340066df5af2 upstream.
If the caller's fs{g,u}id aren't mapped in the mount's idmapping we can
return early and skip the check whether the mapped fs{g,u}id also have a
mapping in the filesystem's idmapping. If the fs{g,u}id aren't mapped in
the mount's idmapping they consequently can't be mapped in the
filesystem's idmapping. So there's no point in checking that.
Link: https://lore.kernel.org/r/20211123114227.3124056-4-brauner@xxxxxxxxxx (v1)
Link: https://lore.kernel.org/r/20211130121032.3753852-4-brauner@xxxxxxxxxx (v2)
Link: https://lore.kernel.org/r/20211203111707.3901969-4-brauner@xxxxxxxxxx
Cc: Seth Forshee <sforshee@xxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
CC: linux-fsdevel@xxxxxxxxxxxxxxx
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Seth Forshee <sforshee@xxxxxxxxxxxxxxxx>
Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/fs.h | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1697,10 +1697,18 @@ static inline void inode_fsgid_set(struc
static inline bool fsuidgid_has_mapping(struct super_block *sb,
struct user_namespace *mnt_userns)
{
- struct user_namespace *s_user_ns = sb->s_user_ns;
+ struct user_namespace *fs_userns = sb->s_user_ns;
+ kuid_t kuid;
+ kgid_t kgid;
- return kuid_has_mapping(s_user_ns, mapped_fsuid(mnt_userns)) &&
- kgid_has_mapping(s_user_ns, mapped_fsgid(mnt_userns));
+ kuid = mapped_fsuid(mnt_userns);
+ if (!uid_valid(kuid))
+ return false;
+ kgid = mapped_fsgid(mnt_userns);
+ if (!gid_valid(kgid))
+ return false;
+ return kuid_has_mapping(fs_userns, kuid) &&
+ kgid_has_mapping(fs_userns, kgid);
}
extern struct timespec64 current_time(struct inode *inode);
Patches currently in stable-queue which might be from brauner@xxxxxxxxxx are
queue-5.15/fs-account-for-group-membership.patch
queue-5.15/fs-use-low-level-mapping-helpers.patch
queue-5.15/fs-move-mapping-helpers.patch
queue-5.15/fs-remove-unused-low-level-mapping-helpers.patch
queue-5.15/fs-tweak-fsuidgid_has_mapping.patch
queue-5.15/fs-add-i_user_ns-helper.patch
queue-5.15/fs-add-is_idmapped_mnt-helper.patch
queue-5.15/fs-support-mapped-mounts-of-mapped-filesystems.patch
queue-5.15/fs-fix-acl-translation.patch
queue-5.15/fs-port-higher-level-mapping-helpers.patch
queue-5.15/docs-update-mapping-documentation.patch
queue-5.15/fs-account-for-filesystem-mappings.patch
