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To:     Casey Schaufler <casey@schaufler-ca.com>
Cc:     linux-security-module@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>
From:   Jens Axboe <axboe@kernel.dk>
Subject: [PATCH] Revert "Smack: Handle io_uring kernel thread privileges"
Message-ID: <04c7c410-08e8-626a-795e-b77db6666804@kernel.dk>
Date:   Thu, 25 Mar 2021 18:42:50 -0600
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This reverts commit 942cb357ae7d9249088e3687ee6a00ed2745a0c7.

The io_uring PF_IO_WORKER threads no longer have PF_KTHREAD set, so no
need to special case them for credential checks.

Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 security/smack/smack_access.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 7eabb448acab..efe2406a3960 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -688,10 +688,9 @@ bool smack_privileged_cred(int cap, const struct cred *cred)
 bool smack_privileged(int cap)
 {
 	/*
-	 * Kernel threads may not have credentials we can use.
-	 * The io_uring kernel threads do have reliable credentials.
+	 * All kernel tasks are privileged
 	 */
-	if ((current->flags & (PF_KTHREAD | PF_IO_WORKER)) == PF_KTHREAD)
+	if (unlikely(current->flags & PF_KTHREAD))
 		return true;
 
 	return smack_privileged_cred(cap, current_cred());
-- 
2.31.0

-- 
Jens Axboe