From 5f65e5ca286126a60f62c8421b77c2018a482b8a Mon Sep 17 00:00:00 2001
From: Seth Forshee <seth.forshee@canonical.com>
Date: Tue, 26 Apr 2016 14:36:24 -0500
Subject: [PATCH] cred: Reject inodes with invalid ids in set_create_file_as()
Using INVALID_[UG]ID for the LSM file creation context doesn't
make sense, so return an error if the inode passed to
set_create_file_as() has an invalid id.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
kernel/cred.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/cred.c b/kernel/cred.c
index 0c0cd8a622852..5f264fb5737dc 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -689,6 +689,8 @@ EXPORT_SYMBOL(set_security_override_from_ctx);
*/
int set_create_files_as(struct cred *new, struct inode *inode)
{
+ if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
+ return -EINVAL;
new->fsuid = inode->i_uid;
new->fsgid = inode->i_gid;
return security_kernel_create_files_as(new, inode);
--
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