Re: [PATCH v3] dmaengine: nbpfaxi: Fix setting channel irqs in probe()

[Dan Carpenter]

On Tue, Jul 14, 2026 at 09:44:22AM +0200, Taedcke, Christian wrote:
> 
> 
> On 7/9/2026 12:38 PM, Dan Carpenter wrote:
> > On Fri, Jul 03, 2026 at 09:56:12AM +0200, Christian Taedcke via B4 Relay wrote:
> >> From: Christian Taedcke <christian.taedcke@xxxxxxxxxxxxxxx>
> >>
> >> When one irq is used for errors and each channel gets a dedicated irq,
> >> the total number of irqs is num_channels + 1. If the error irq is not
> >> the last entry in irqbuf[] but an earlier one, the loop assigning
> >> per-channel irqs terminates one iteration too early and the last
> >> channel is left without an irq.
> >>
> >> Iterate over all collected irqs instead of num_channels so the
> >> error-irq skip does not shorten the effective channel count.
> >>
> >> Fixes: 188c6ba1dd92 ("dmaengine: nbpfaxi: Fix memory corruption in probe()")
> >> Cc: stable@xxxxxxxxxxxxxxx
> >> Signed-off-by: Christian Taedcke <christian.taedcke@xxxxxxxxxxxxxxx>
> >> ---
> >> Changes in v3:
> >> - Guard against out-of-bound writes to chan in case of an invalid eirq.
> >> - Link to v2: https://patch.msgid.link/20260702-upstreaming-nbpfaxi-v1-v2-1-e6d6b178a278@xxxxxxxxxxxxxxx
> >>
> >> Changes in v2:
> >> - Advance chan only when assigning a real irq to fix out-of-bounds
> >>   memory access.
> >> - Remove now redundant ARRAY_SIZE(irqbuf) check.
> >> - Link to v1: https://patch.msgid.link/20260702-upstreaming-nbpfaxi-v1-v1-1-fd8ea8830cea@xxxxxxxxxxxxxxx
> >>
> >> To: christian.taedcke-oss@xxxxxxxxxxxxxxx
> >> To: Vinod Koul <vkoul@xxxxxxxxxx>
> >> To: Frank Li <Frank.Li@xxxxxxxxxx>
> >> To: Dan Carpenter <error27@xxxxxxxxx>
> >> Cc: dmaengine@xxxxxxxxxxxxxxx
> >> Cc: linux-kernel@xxxxxxxxxxxxxxx
> >> ---
> >>  drivers/dma/nbpfaxi.c | 8 ++++----
> >>  1 file changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/dma/nbpfaxi.c b/drivers/dma/nbpfaxi.c
> >> index 05d7321629cc..b1f06f0bd0d5 100644
> >> --- a/drivers/dma/nbpfaxi.c
> >> +++ b/drivers/dma/nbpfaxi.c
> >> @@ -1374,14 +1374,14 @@ static int nbpf_probe(struct platform_device *pdev)
> >>  		if (irqs == num_channels + 1) {
> >>  			struct nbpf_channel *chan;
> >>  
> >> -			for (i = 0, chan = nbpf->chan; i < num_channels;
> >> -			     i++, chan++) {
> >> +			for (i = 0, chan = nbpf->chan; i < irqs; i++) {
> >>  				/* Skip the error IRQ */
> >>  				if (irqbuf[i] == eirq)
> >> -					i++;
> >> -				if (i >= ARRAY_SIZE(irqbuf))
> >> +					continue;
> >> +				if (chan >= nbpf->chan + num_channels)
> > 
> > Prefer my check, but sure...
> 
> Thank you for your review, i send a new version where i try to use your preferred check.
> > 
> > It's pretty annoying that sashiko bot doesn't CC the CC list.
> 
> Is there anything i can do to improve this? Should i reply to the sashiko bot comments and also send this to the CC list?
> 

Not at all.  Just random grumbling.

regards,
dan carpenter