FAILED: patch "[PATCH] net: dsa: microchip: Don't free uninitialized ksz_irq" failed to apply to 6.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 25b62cc5b22c45face094ae3e8717258e46d1d19
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025120258-cupid-regally-5bc2@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 25b62cc5b22c45face094ae3e8717258e46d1d19 Mon Sep 17 00:00:00 2001
From: "Bastien Curutchet (Schneider Electric)" <bastien.curutchet@bootlin.com>
Date: Thu, 20 Nov 2025 10:12:02 +0100
Subject: [PATCH] net: dsa: microchip: Don't free uninitialized ksz_irq

If something goes wrong at setup, ksz_irq_free() can be called on
uninitialized ksz_irq (for example when ksz_ptp_irq_setup() fails). It
leads to freeing uninitialized IRQ numbers and/or domains.

Use dsa_switch_for_each_user_port_continue_reverse() in the error path
to iterate only over the fully initialized ports.

Cc: stable@vger.kernel.org
Fixes: cc13ab18b201 ("net: dsa: microchip: ptp: enable interrupt for timestamping")
Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
Link: https://patch.msgid.link/20251120-ksz-fix-v6-3-891f80ae7f8f@bootlin.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index e684568a4eda..a927055423f3 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -3082,7 +3082,7 @@ static int ksz_setup(struct dsa_switch *ds)
 			ksz_ptp_irq_free(ds, dp->index);
 out_pirq:
 	if (dev->irq > 0)
-		dsa_switch_for_each_user_port(dp, dev->ds)
+		dsa_switch_for_each_user_port_continue_reverse(dp, dev->ds)
 			ksz_irq_free(&dev->ports[dp->index].pirq);
 out_girq:
 	if (dev->irq > 0)