Re: [PATCH] Revert "Smack: Handle io_uring kernel thread privileges"
From: Casey Schaufler <casey@schaufler-ca.com>
Date: 2021-03-26 16:01:20
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On 3/25/2021 5:42 PM, Jens Axboe wrote:
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.
Could you cite the commit making that change? I wouldn't want to see this change back-ported to a kernel that doesn't have that change as well.
quoted hunk ↗ jump to hunk
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());