[PATCH net] net: mctp: Consistent peer address handling in ioctl tag allocation

[PATCH net] net: mctp: Consistent peer address handling in ioctl tag allocation

[John Wang]

When executing ioctl to allocate tags, if the peer address is 0,
mctp_alloc_local_tag now replaces it with 0xff. However, during tag
dropping, this replacement is not performed, potentially causing the key
not to be dropped as expected.

Signed-off-by: John Wang <wangzhiqiang02@ieisystem.com>
Change-Id: I9c75aa8aff4bc048dd3be563f7f50a6fb14dc028
---
 net/mctp/af_mctp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index de52a9191da0..43288b408fde 100644
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -486,6 +486,9 @@ static int mctp_ioctl_droptag(struct mctp_sock *msk, bool tagv2,
 	tag = ctl.tag & MCTP_TAG_MASK;
 	rc = -EINVAL;
 
+	if (ctl.peer_addr == MCTP_ADDR_NULL)
+		ctl.peer_addr = MCTP_ADDR_ANY;
+
 	spin_lock_irqsave(&net->mctp.keys_lock, flags);
 	hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
 		/* we do an irqsave here, even though we know the irq state,
-- 
2.34.1

Re: [PATCH net] net: mctp: Consistent peer address handling in ioctl tag allocation

[Simon Horman]

On Tue, Jul 30, 2024 at 11:40:31AM +0800, John Wang wrote:
> When executing ioctl to allocate tags, if the peer address is 0,
> mctp_alloc_local_tag now replaces it with 0xff. However, during tag
> dropping, this replacement is not performed, potentially causing the key
> not to be dropped as expected.
> 
> Signed-off-by: John Wang <wangzhiqiang02@ieisystem.com>
> Change-Id: I9c75aa8aff4bc048dd3be563f7f50a6fb14dc028

Hi John,

This is not a full review, so I would recommend waiting for feedback
from others, but please:

1. Do not include the Change-Id as it is not obvious what public
   resource it references
2. As this is a fix targeted at net, please do include a Fixes tag,
   indicating the commit where this user-visible problem first
   manifested.

Also, as an aside, please wait 24h between posting updated patches.
Link: https://docs.kernel.org/process/maintainer-netdev.html

...