Re: [PATCH] ice: Fix some null pointer dereference issues in ice_ptp.c

From: Kunwu Chan
Date: Mon Dec 11 2023 - 04:32:24 EST


Thanks for your suggestion.

I made the patch based on linux-next.git(tag:next-20231211).

Our code is just self-similar, i didn't override the old name.
I keep the logic as it was before.
The newest code is:

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/net/ethernet/intel/ice/ice_ptp.c#n2747

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/net/ethernet/intel/ice/ice_ptp.c#n2993

I'll update v2 patch with:
1. update suject prefix to "[PATCH v2 iwl-next]"
2. remove 'dev_err'


Thanks again,
Kunwu

On 2023/12/11 15:15, Przemek Kitszel wrote:
On 12/11/23 07:26, Kunwu Chan wrote:
devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: d938a8cca88a ("ice: Auxbus devices & driver for E822 TS")
Cc: Kunwu Chan <kunwu.chan@xxxxxxxxxxx>
Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>

I would suggest adding "iwl-net" as a target here

---
  drivers/net/ethernet/intel/ice/ice_ptp.c | 6 ++++++
  1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 1eddcbe89b0c..59794ce4f243 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -2668,6 +2668,8 @@ static int ice_ptp_register_auxbus_driver(struct ice_pf *pf)
      name = devm_kasprintf(dev, GFP_KERNEL, "ptp_aux_dev_%u_%u_clk%u",
                    pf->pdev->bus->number, PCI_SLOT(pf->pdev->devfn),
                    ice_get_ptp_src_clock_index(&pf->hw));
+    if (!name)
+        return -ENOMEM;
      aux_driver->name = name;
      aux_driver->shutdown = ice_ptp_auxbus_shutdown;
@@ -2929,6 +2931,10 @@ static int ice_ptp_create_auxbus_device(struct ice_pf *pf)
      name = devm_kasprintf(dev, GFP_KERNEL, "ptp_aux_dev_%u_%u_clk%u",
                    pf->pdev->bus->number, PCI_SLOT(pf->pdev->devfn),
                    ice_get_ptp_src_clock_index(&pf->hw));
+    if (!name) {
+        dev_err(dev, "Failed to allocate memory\n");

Kuba @ [1]:
no warnings on allocation failures, there will be a splat for GFP_KERNEL
(checkpatch should catch this)

[1] https://lore.kernel.org/netdev/20231206195304.6226771d@xxxxxxxxxx/T/

so just "return -ENOMEM" would be sufficient

+        return -ENOMEM;
+    }
      aux_dev->name = name;
      aux_dev->id = id;

I didn't checked but having same code in two places raises questions.
Are you overwriting old name here, or our code is just self similar?