FAILED: patch "[PATCH] PCI: imx6: Avoid dereferencing a NULL clock name" failed to apply to 6.18-stable tree

[Sasha Levin <sashal@kernel.org>]

The patch below does not apply to the 6.18-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-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x e60d0d4dfddfac3058753a1c2255251401c92dad
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107051121-failed-6.18-e60d0d4dfddf@kernel.org' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Thanks,
Sasha

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

From e60d0d4dfddfac3058753a1c2255251401c92dad Mon Sep 17 00:00:00 2001
From: Rudi Heitbaum <rudi@heitbaum.com>
Date: Mon, 14 Sep 2026 12:35:31 +0000
Subject: [PATCH] PCI: imx6: Avoid dereferencing a NULL clock name

of_clk_bulk_get() leaves 'clk_bulk_data->id' as NULL for every clock that
has no matching entry in "clock-names", which is legal: a node may list
more "clocks" phandles than it names. Both scans of the bulk array
dereference that id unconditionally, so such a node oopses during probe.

The loop in imx_pcie_probe() has been wrong since it was written. The
loop in imx_setup_phy_mpll() was not: it read a fixed clks[] whose ids
came from the driver's own clk_names[] and were never NULL, and only
became wrong when the driver moved to the bulk array.

Check 'clk_bulk_data->id' before dereferencing it in both.

Fixes: f6a1fdfc78e2 ("PCI: imx6: Use devm_clk_bulk_get_all() to fetch clocks")
Fixes: d8574ce57d76 ("PCI: imx6: Add external reference clock input mode support")
Signed-off-by: Rudi Heitbaum <rudi@heitbaum.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/am8iBwJSEhYhWTqk@6cfee64030a6/
Link: https://patch.msgid.link/aqfqE4OLhnN4a1lW@b65e9c1eb12f
---
 drivers/pci/controller/dwc/pci-imx6.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 54e104679da07..b7390da1ae35a 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -584,7 +584,7 @@ static int imx_setup_phy_mpll(struct imx_pcie *imx_pcie)
 		return 0;
 
 	for (i = 0; i < imx_pcie->num_clks; i++)
-		if (strncmp(clks[i].id, "pcie_phy", 8) == 0)
+		if (clks[i].id && strncmp(clks[i].id, "pcie_phy", 8) == 0)
 			phy_rate = clk_get_rate(clks[i].clk);
 
 	switch (phy_rate) {
@@ -1902,7 +1902,8 @@ static int imx_pcie_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, imx_pcie->num_clks,
 				     "failed to get clocks\n");
 	for (i = 0; i < imx_pcie->num_clks; i++)
-		if (strncmp(imx_pcie->clks[i].id, "extref", 6) == 0)
+		if (imx_pcie->clks[i].id &&
+		    strncmp(imx_pcie->clks[i].id, "extref", 6) == 0)
 			imx_pcie->enable_ext_refclk = true;
 
 	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_PHYDRV)) {
-- 
2.53.0