[PATCH next] ice, irdma: fix an off by one in error handling code

[PATCH next] ice, irdma: fix an off by one in error handling code

[Dan Carpenter]

If we don't allocate the MIN number of IRQs then we need to free what
we have and return -ENOMEM.  The problem is this loop is off by one
so it frees an entry that wasn't allocated and it doesn't free the
first entry where i == 0.

Fixes: 3e0d3cb3fbe0 ("ice, irdma: move interrupts code to irdma")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/infiniband/hw/irdma/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/irdma/main.c b/drivers/infiniband/hw/irdma/main.c
index 1ee8969595d3..5fc081ca8905 100644
--- a/drivers/infiniband/hw/irdma/main.c
+++ b/drivers/infiniband/hw/irdma/main.c
@@ -221,7 +221,7 @@ static int irdma_init_interrupts(struct irdma_pci_f *rf, struct ice_pf *pf)
 			break;
 
 	if (i < IRDMA_MIN_MSIX) {
-		for (; i > 0; i--)
+		while (--i >= 0)
 			ice_free_rdma_qvector(pf, &rf->msix_entries[i]);
 
 		kfree(rf->msix_entries);
-- 
2.47.2

Re: [PATCH next] ice, irdma: fix an off by one in error handling code

[Michal Swiatkowski]

On Wed, Feb 12, 2025 at 06:25:44PM +0300, Dan Carpenter wrote:
> If we don't allocate the MIN number of IRQs then we need to free what
> we have and return -ENOMEM.  The problem is this loop is off by one
> so it frees an entry that wasn't allocated and it doesn't free the
> first entry where i == 0.
> 
> Fixes: 3e0d3cb3fbe0 ("ice, irdma: move interrupts code to irdma")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  drivers/infiniband/hw/irdma/main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/irdma/main.c b/drivers/infiniband/hw/irdma/main.c
> index 1ee8969595d3..5fc081ca8905 100644
> --- a/drivers/infiniband/hw/irdma/main.c
> +++ b/drivers/infiniband/hw/irdma/main.c
> @@ -221,7 +221,7 @@ static int irdma_init_interrupts(struct irdma_pci_f *rf, struct ice_pf *pf)
>  			break;
>  
>  	if (i < IRDMA_MIN_MSIX) {
> -		for (; i > 0; i--)
> +		while (--i >= 0)
>  			ice_free_rdma_qvector(pf, &rf->msix_entries[i]);
>  
>  		kfree(rf->msix_entries);

Przemek pointed that in the review, but somehow I missed that :( .
Thanks for fixing:
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>

> -- 
> 2.47.2
> 

Re: [PATCH next] ice, irdma: fix an off by one in error handling code

[Tony Nguyen]

On 2/12/2025 7:25 AM, Dan Carpenter wrote:
> If we don't allocate the MIN number of IRQs then we need to free what
> we have and return -ENOMEM.  The problem is this loop is off by one
> so it frees an entry that wasn't allocated and it doesn't free the
> first entry where i == 0.
> 
> Fixes: 3e0d3cb3fbe0 ("ice, irdma: move interrupts code to irdma")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Thanks for the patch Dan. I've applied this to iwl-next since it 
originated from there and I'd like to bundle this with the other fixes 
related to the series.

Thanks,
Tony

> ---
>   drivers/infiniband/hw/irdma/main.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/irdma/main.c b/drivers/infiniband/hw/irdma/main.c
> index 1ee8969595d3..5fc081ca8905 100644
> --- a/drivers/infiniband/hw/irdma/main.c
> +++ b/drivers/infiniband/hw/irdma/main.c
> @@ -221,7 +221,7 @@ static int irdma_init_interrupts(struct irdma_pci_f *rf, struct ice_pf *pf)
>   			break;
>   
>   	if (i < IRDMA_MIN_MSIX) {
> -		for (; i > 0; i--)
> +		while (--i >= 0)
>   			ice_free_rdma_qvector(pf, &rf->msix_entries[i]);
>   
>   		kfree(rf->msix_entries);