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authorChristian Brauner <christian.brauner@ubuntu.com>2021-01-21 16:19:26 +0300
committerChristian Brauner <christian.brauner@ubuntu.com>2021-01-24 16:27:16 +0300
commit2f221d6f7b881d95de1f356a3097d755ab1e47d4 (patch)
tree3d136e3ade1492f1ab59e09546ffa6f2d723f76d /mm/shmem.c
parent21cb47be6fb9ece7e6ee63f6780986faa384a77c (diff)
downloadlinux-2f221d6f7b881d95de1f356a3097d755ab1e47d4.tar.xz
attr: handle idmapped mounts
When file attributes are changed most filesystems rely on the setattr_prepare(), setattr_copy(), and notify_change() helpers for initialization and permission checking. Let them handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Helpers that perform checks on the ia_uid and ia_gid fields in struct iattr assume that ia_uid and ia_gid are intended values and have already been mapped correctly at the userspace-kernelspace boundary as we already do today. 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/20210121131959.646623-8-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 1c68c9edba5e..1cb451e131ec 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1087,7 +1087,7 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
int error;
- error = setattr_prepare(dentry, attr);
+ error = setattr_prepare(&init_user_ns, dentry, attr);
if (error)
return error;
@@ -1141,7 +1141,7 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
}
}
- setattr_copy(inode, attr);
+ setattr_copy(&init_user_ns, inode, attr);
if (attr->ia_valid & ATTR_MODE)
error = posix_acl_chmod(inode, inode->i_mode);
return error;