[PATCH] Smack: Handle io_uring kernel thread privileges.
by Casey Schaufler
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(a)kernel.dk>
Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com>
---
security/smack/smack_access.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index efe2406a3960..7eabb448acab 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -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());
2 months, 1 week