This is a note to let you know that I've just added the patch titled
ibmvnic: Handle DMA unmapping of login buffs in release functions
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ibmvnic-handle-dma-unmapping-of-login-buffs-in-release-functions.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d78a671eb8996af19d6311ecdee9790d2fa479f0 Mon Sep 17 00:00:00 2001
From: Nick Child <nnac123@xxxxxxxxxxxxx>
Date: Wed, 9 Aug 2023 17:10:36 -0500
Subject: ibmvnic: Handle DMA unmapping of login buffs in release functions
From: Nick Child <nnac123@xxxxxxxxxxxxx>
commit d78a671eb8996af19d6311ecdee9790d2fa479f0 upstream.
Rather than leaving the DMA unmapping of the login buffers to the
login response handler, move this work into the login release functions.
Previously, these functions were only used for freeing the allocated
buffers. This could lead to issues if there are more than one
outstanding login buffer requests, which is possible if a login request
times out.
If a login request times out, then there is another call to send login.
The send login function makes a call to the login buffer release
function. In the past, this freed the buffers but did not DMA unmap.
Therefore, the VIOS could still write to the old login (now freed)
buffer. It is for this reason that it is a good idea to leave the DMA
unmap call to the login buffers release function.
Since the login buffer release functions now handle DMA unmapping,
remove the duplicate DMA unmapping in handle_login_rsp().
Fixes: dff515a3e71d ("ibmvnic: Harden device login requests")
Signed-off-by: Nick Child <nnac123@xxxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230809221038.51296-3-nnac123@xxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/ibm/ibmvnic.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -873,12 +873,22 @@ static int ibmvnic_login(struct net_devi
static void release_login_buffer(struct ibmvnic_adapter *adapter)
{
+ if (!adapter->login_buf)
+ return;
+
+ dma_unmap_single(&adapter->vdev->dev, adapter->login_buf_token,
+ adapter->login_buf_sz, DMA_TO_DEVICE);
kfree(adapter->login_buf);
adapter->login_buf = NULL;
}
static void release_login_rsp_buffer(struct ibmvnic_adapter *adapter)
{
+ if (!adapter->login_rsp_buf)
+ return;
+
+ dma_unmap_single(&adapter->vdev->dev, adapter->login_rsp_buf_token,
+ adapter->login_rsp_buf_sz, DMA_FROM_DEVICE);
kfree(adapter->login_rsp_buf);
adapter->login_rsp_buf = NULL;
}
@@ -4298,11 +4308,6 @@ static int handle_login_rsp(union ibmvni
struct ibmvnic_login_buffer *login = adapter->login_buf;
int i;
- dma_unmap_single(dev, adapter->login_buf_token, adapter->login_buf_sz,
- DMA_TO_DEVICE);
- dma_unmap_single(dev, adapter->login_rsp_buf_token,
- adapter->login_rsp_buf_sz, DMA_FROM_DEVICE);
-
/* If the number of queues requested can't be allocated by the
* server, the login response will return with code 1. We will need
* to resend the login buffer with fewer queues requested.
Patches currently in stable-queue which might be from nnac123@xxxxxxxxxxxxx are
queue-5.4/ibmvnic-handle-dma-unmapping-of-login-buffs-in-release-functions.patch
