Thread (30 messages) 30 messages, 6 authors, 2021-02-12

Re: Conflict with Mickaël Salaün's blacklist patches [was [PATCH v5 0/4] Add EFI_CERT_X509_GUID support for dbx/mokx entries]

From: Eric Snowberg <eric.snowberg@oracle.com>
Date: 2021-02-08 23:07:29
Also in: keyrings, linux-kbuild, lkml

quoted hunk ↗ jump to hunk
On Feb 6, 2021, at 11:30 AM, Mickaël Salaün [off-list ref] wrote:

On 06/02/2021 02:14, Eric Snowberg wrote:
quoted
I have done some additional testing, I am seeing a regression. The blacklist 
keyring is no longer picking up any of the hashes from the dbx during boot. 
I backed out the merge with my changes  (fdbbe7ceeb95090d09c33ce0497e0394c82aa33d) 
and still see the regression.  I then backed out Mickaël merge
(5bf1adccf5c41dbdd51d1f4de220d335d9548598) and it fixes the regression.

On a x86 with the updated dbx from uefi.org, I’d expect to see 234 bin hash entries
in the blacklist keyring.  With the current merged code, there is none.
Hum, I missed a part in refactoring (commit
f78e50c8f750c0ac6767ac1ed006360cf77c56c4). :/
Could you please test the following patch?
diff --git a/certs/blacklist.c b/certs/blacklist.c
index 07c592ae5307..f998a2e85ddc 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c
@@ -197,13 +197,16 @@ int mark_hash_blacklisted(const u8 *hash, size_t
hash_len,
               enum blacklist_hash_type hash_type)
{
       const char *buffer;
+       int err;

       buffer = get_raw_hash(hash, hash_len, hash_type);
       if (IS_ERR(buffer))
               return PTR_ERR(buffer);
+       err = mark_raw_hash_blacklisted(buffer);
       kfree(buffer);
-       return 0;
+       return err;
}
I applied this patch, it works better, but there is still a regression. 
Most of the hashes show up in the blacklist keyring now.  However some 
do not, here is what I see in the log during boot:

[    2.321876] blacklist: Problem blacklisting hash (-13)
[    2.322729] blacklist: Problem blacklisting hash (-13)
[    2.323549] blacklist: Problem blacklisting hash (-13)
[    2.324369] blacklist: Problem blacklisting hash (-13)
Is it possible to test these kind of dbx blacklist with Qemu?
Yes, just use OVMF. 
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help