tool: don't grant PDs their parent's fault EP cap - #613
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midnightveil
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Some notes: this was reported by a user, and was also (independently!) noted in @zaklogician's least-privilege proofs for Microkit. |
The capDL migration in 9d6b4e0 unintentionally gave child PDs a cap to their parent's fault endpoint. In 2.3.1, this lets a PD send the parent fake faults with arbitrary messages. In 2.3.0 and earlier, it lets a PD receive, and so consume, fault IPCs meant for the parent. Fix this by not granting the cap. Signed-off-by: Bill Nguyen <bill.nguyen@unsw.edu.au>
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The capDL migration in 9d6b4e0 unintentionally gave child PDs a cap to their parent's fault endpoint. Oops.
In 2.3.1, this lets a PD send the parent fake faults with arbitrary messages. In 2.3.0 and earlier, it lets a PD receive, and so consume, fault IPCs meant for the parent.
Fix this by not granting the cap.