[PATCH net v2] net/smc: Remove validation of reserved bits in CLC Decline message

[PATCH net v2] net/smc: Remove validation of reserved bits in CLC Decline message

[Mahanta Jambigi]

Currently SMC code is validating the reserved bits while parsing the incoming
CLC decline message & when this validation fails, its treated as a protocol
error. As a result, the SMC connection is terminated instead of falling back to
TCP. As per RFC7609[1] specs we shouldn't be validating the reserved bits that
is part of CLC message. This patch fixes this issue.

CLC Decline message format can viewed here[2].

[1] https://datatracker.ietf.org/doc/html/rfc7609#page-92
[2] https://datatracker.ietf.org/doc/html/rfc7609#page-105

Fixes: 8ade200c269f ("net/smc: add v2 format of CLC decline message")
Signed-off-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
---
 net/smc/smc_clc.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 5a4db151fe95..08be56dfb3f2 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -426,8 +426,6 @@ smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
 {
 	struct smc_clc_msg_hdr *hdr = &dclc->hdr;
 
-	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
-		return false;
 	if (hdr->version == SMC_V1) {
 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline))
 			return false;
-- 
2.48.1

Re: [PATCH net v2] net/smc: Remove validation of reserved bits in CLC Decline message

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue,  2 Sep 2025 10:20:41 +0200 you wrote:
> Currently SMC code is validating the reserved bits while parsing the incoming
> CLC decline message & when this validation fails, its treated as a protocol
> error. As a result, the SMC connection is terminated instead of falling back to
> TCP. As per RFC7609[1] specs we shouldn't be validating the reserved bits that
> is part of CLC message. This patch fixes this issue.
> 
> CLC Decline message format can viewed here[2].
> 
> [...]

Here is the summary with links:
  - [net,v2] net/smc: Remove validation of reserved bits in CLC Decline message
    https://git.kernel.org/netdev/net/c/cc282f73bc0c

You are awesome, thank you!
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