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ibmvnic: Handle DMA unmapping of login buffs in release functions

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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@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230809221038.51296-3-nnac123@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nick Child 2023-08-09 17:10:36 -05:00 committed by Greg Kroah-Hartman
parent d66a27113e
commit 0a3b5893c6
1 changed files with 10 additions and 5 deletions
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15
drivers/net/ethernet/ibm/ibmvnic.c
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@ -873,12 +873,22 @@ static int ibmvnic_login(struct net_device *netdev)
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 ibmvnic_crq *login_rsp_crq,
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.