[PATCH RESEND v2 09/18] fs: Refuse uid/gid changes which don't map into s_user_ns
From: Seth Forshee <hidden>
Date: 2016-01-04 18:04:26
Also in:
dm-devel, linux-bcache, linux-fsdevel, lkml, selinux
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
Add checks to inode_change_ok to verify that uid and gid changes will map into the superblock's user namespace. If they do not fail with -EOVERFLOW. This cannot be overriden with ATTR_FORCE. Signed-off-by: Seth Forshee <redacted> Acked-by: Serge Hallyn <redacted> --- fs/attr.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/fs/attr.c b/fs/attr.c
index 6530ced19697..55b46e3aa888 100644
--- a/fs/attr.c
+++ b/fs/attr.c@@ -42,6 +42,17 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr) return error; } + /* + * Verify that uid/gid changes are valid in the target namespace + * of the superblock. This cannot be overriden using ATTR_FORCE. + */ + if (ia_valid & ATTR_UID && + from_kuid(inode->i_sb->s_user_ns, attr->ia_uid) == (uid_t)-1) + return -EOVERFLOW; + if (ia_valid & ATTR_GID && + from_kgid(inode->i_sb->s_user_ns, attr->ia_gid) == (gid_t)-1) + return -EOVERFLOW; + /* If force is set do it anyway. */ if (ia_valid & ATTR_FORCE) return 0;
--
1.9.1
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