[PATCH 4.4 36/39] rxrpc: Fix rxkad token xdr encoding
From: Greg Kroah-Hartman
Date: Mon Oct 12 2020 - 09:34:01 EST
From: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
[ Upstream commit 56305118e05b2db8d0395bba640ac9a3aee92624 ]
The session key should be encoded with just the 8 data bytes and
no length; ENCODE_DATA precedes it with a 4 byte length, which
confuses some existing tools that try to parse this format.
Add an ENCODE_BYTES macro that does not include a length, and use
it for the key. Also adjust the expected length.
Note that commit 774521f353e1d ("rxrpc: Fix an assertion in
rxrpc_read()") had fixed a BUG by changing the length rather than
fixing the encoding. The original length was correct.
Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)")
Signed-off-by: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/rxrpc/ar-key.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index 91d43ab3a9610..543d200f4fa14 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -1149,6 +1149,14 @@ static long rxrpc_read(const struct key *key,
goto fault; \
xdr += (_l + 3) >> 2; \
} while(0)
+#define ENCODE_BYTES(l, s) \
+ do { \
+ u32 _l = (l); \
+ memcpy(xdr, (s), _l); \
+ if (_l & 3) \
+ memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3)); \
+ xdr += (_l + 3) >> 2; \
+ } while(0)
#define ENCODE64(x) \
do { \
__be64 y = cpu_to_be64(x); \
@@ -1177,7 +1185,7 @@ static long rxrpc_read(const struct key *key,
case RXRPC_SECURITY_RXKAD:
ENCODE(token->kad->vice_id);
ENCODE(token->kad->kvno);
- ENCODE_DATA(8, token->kad->session_key);
+ ENCODE_BYTES(8, token->kad->session_key);
ENCODE(token->kad->start);
ENCODE(token->kad->expiry);
ENCODE(token->kad->primary_flag);
--
2.25.1