Smack: Handle io_uring kernel thread privileges

Smack assumes that kernel threads are privileged for smackfs
operations. This was necessary because the credential of the
kernel thread was not related to a user operation. With io_uring
the credential does reflect a user's rights and can be used.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
This commit is contained in:
Casey Schaufler 2020-12-22 15:34:24 -08:00
parent 9b0072e2b2
commit 942cb357ae
1 changed files with 3 additions and 2 deletions

View File

@ -688,9 +688,10 @@ bool smack_privileged_cred(int cap, const struct cred *cred)
bool smack_privileged(int cap)
{
/*
* All kernel tasks are privileged
* Kernel threads may not have credentials we can use.
* The io_uring kernel threads do have reliable credentials.
*/
if (unlikely(current->flags & PF_KTHREAD))
if ((current->flags & (PF_KTHREAD | PF_IO_WORKER)) == PF_KTHREAD)
return true;
return smack_privileged_cred(cap, current_cred());