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Smack: Handle io_uring kernel thread privileges

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[ Upstream commit 942cb357ae7d9249088e3687ee6a00ed2745a0c7 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Casey Schaufler 2020-12-22 15:34:24 -08:00 committed by Greg Kroah-Hartman
parent b2ec2b12a4
commit 8f939abd81
1 changed files with 3 additions and 2 deletions
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5
security/smack/smack_access.c
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@ -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());