[PATCH 3/7] lib/digsig: fix dereference of NULL user_key_payload
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From: jmorris@namei.org (James Morris)
Date: 2017-10-03 10:53:02
Also in:
keyrings, linux-fscrypt, stable
On Thu, 28 Sep 2017, Eric Biggers wrote:
From: Eric Biggers <redacted>
digsig_verify() requests a user key, then accesses its payload.
However, a revoked key has a NULL payload, and we failed to check for
this. request_key() *does* skip revoked keys, but there is still a
window where the key can be revoked before we acquire its semaphore.
Fix it by checking for a NULL payload, treating it like a key which was
already revoked at the time it was requested.
Fixes: 051dbb918c7f ("crypto: digital signature verification support")
Cc: <redacted> [v3.3+]
Signed-off-by: Eric Biggers <redacted>Reviewed-by: James Morris <redacted> -- James Morris [off-list ref] -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html