[PATCH RESEND v2 08/18] cred: Reject inodes with invalid ids in set_create_file_as()

Seth Forshee
2016-01-04T18:03:47Z

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-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
Acked-by: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
---
kernel/cred.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/cred.c b/kernel/cred.c
index 71179a09c1d6..ff8606f77d90 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);
--
1.9.1

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