* Re: [PATCH] scsi: pm8001: use rollback index when freeing MSI-X vectors
2026-08-24 11:36 [PATCH] scsi: pm8001: use rollback index when freeing MSI-X vectors Runyu Xiao
@ 2026-08-24 11:53 ` sashiko-bot
2026-08-28 11:30 ` Jinpu Wang
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: sashiko-bot @ 2026-08-24 11:53 UTC (permalink / raw)
To: Runyu Xiao; +Cc: linux-scsi
Thank you for your contribution! Sashiko AI review found 4 potential issue(s) to consider:
Pre-existing issues:
- [High] Probe and allocation error paths fail to unregister IRQ handlers, kill tasklets, and free PCI IRQ vectors.
- [High] Incorrect error jump label in pm8001_pci_probe() bypasses all cleanup.
- [High] Broken fallback to legacy INT-X interrupts when MSI-X vector allocation fails.
- [Medium] Missing teardown of specific memory allocations (pm8001_ha->devices, sha->sas_phy, sha->sas_port) in probe error paths.
--
--- Patch [1]: [PATCH] scsi: pm8001: use rollback index when freeing MSI-X vectors ---
commit 961717b6ef49f9e3b852de4ab73c7119e69629df
Author: Runyu Xiao <runyu.xiao@seu.edu.cn>
scsi: pm8001: use rollback index when freeing MSI-X vectors
pm8001_request_msix() unwinds previously registered handlers with
free_irq() when request_irq() fails. The rollback loop uses the
failing index i for every iteration instead of the already
registered vector index j. This patch uses j for both
pci_irq_vector() and the matching irq_vector entry in the
rollback loop.
Cc: stable@vger.kernel.org
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index e93ea76b565e5..54b35893261a6 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -1029,8 +1029,8 @@ static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha)
> &(pm8001_ha->irq_vector[i]));
> if (rc) {
> for (j = 0; j < i; j++) {
> - free_irq(pci_irq_vector(pm8001_ha->pdev, i),
> - &(pm8001_ha->irq_vector[i]));
> + free_irq(pci_irq_vector(pm8001_ha->pdev, j),
> + &pm8001_ha->irq_vector[j]);
> }
> pci_free_irq_vectors(pm8001_ha->pdev);
> break;
[Severity: High]
This isn't a bug introduced by this patch, but I noticed that probe and
allocation error paths fail to unregister IRQ handlers, kill tasklets, and
free PCI IRQ vectors.
Looking at pm8001_alloc() in drivers/scsi/pm8001/pm8001_init.c:
rc = pm8001_request_irq(pm8001_ha);
if (rc)
goto err_out;
...
err_out:
return 1;
Does the internal error path here return failure after pm8001_request_irq()
succeeded, bypassing IRQ teardown?
Additionally, the primary teardown function used in probe error paths does
not call pm8001_free_irq(), pm8001_kill_tasklet(), or
pci_free_irq_vectors():
static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
{
...
PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
flush_workqueue(pm8001_wq);
bitmap_free(pm8001_ha->rsvd_tags);
kfree(pm8001_ha);
}
When probe error paths invoke pm8001_free() and kfree(sha):
err_out_ha_free:
pm8001_free(pm8001_ha);
err_out_free:
kfree(sha);
Doesn't this leave dangling IRQ handlers that still point to these freed
structures?
If probe fails after IRQs are requested, it appears the driver leaks the
IRQ handlers, tasklets, and MSI-X vectors. Furthermore, since the handler's
dev_id pointer (pm8001_ha) is freed by pm8001_free(), could a subsequent
interrupt on the shared line or an unmasked device interrupt cause a kernel
panic when the ISR dereferences pm8001_ha?
[Severity: High]
This is a pre-existing issue and was not introduced by the patch under
review, but I noticed the incorrect error jump label in pm8001_pci_probe()
bypasses all cleanup.
In pm8001_pci_probe():
rc = pm8001_init_ccb_tag(pm8001_ha);
if (rc)
goto err_out_enable;
...
err_out_regions:
pci_release_regions(pdev);
err_out_disable:
pci_disable_device(pdev);
err_out_enable:
return rc;
Does this failure path wrongly jump to the end of the function, bypassing
all preceding teardown labels?
If pm8001_init_ccb_tag() fails during probe, the code jumps directly to the
err_out_enable label. This skips all necessary rollback steps, leaking the
Scsi_Host, PCI regions, sas_ha_struct, and pm8001_ha structures, and
leaving the PCI device enabled.
[Severity: Medium]
This isn't a bug introduced by this patch, but there seems to be missing
teardown of specific memory allocations in probe error paths.
In pm8001_free():
static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
{
...
bitmap_free(pm8001_ha->rsvd_tags);
kfree(pm8001_ha);
}
Does this function omit kfree(pm8001_ha->devices), unlike its counterpart
pm8001_pci_remove()?
Also, in the probe error path:
err_out_free:
kfree(sha);
Is it safe for the probe error path to drop the sha structure without
freeing its embedded dynamically allocated arrays (sas_phy and sas_port)?
The structures allocated in pm8001_alloc() (pm8001_ha->devices) and
pm8001_prep_sas_ha_init() (sha->sas_phy and sha->sas_port) are properly
freed during device removal in pm8001_pci_remove(), but seem completely
ignored in the standard probe error paths. Can this lead to memory leaks
on cold paths when initialization fails?
[Severity: High]
This is a pre-existing issue, but I noticed a broken fallback to legacy
INT-X interrupts when MSI-X vector allocation fails.
Looking at pm8001_request_irq():
if (pm8001_use_msix && pci_find_capability(pdev, PCI_CAP_ID_MSIX)) {
rc = pm8001_setup_msix(pm8001_ha);
if (rc) {
pm8001_dbg(pm8001_ha, FAIL,
"pm8001_setup_irq failed [ret: %d]\n", rc);
return rc;
}
Does this exact block break the fallback logic by unconditionally returning
rather than branching to the use_intx label when allocation fails?
If pm8001_setup_msix() fails, the function immediately returns the error.
This entirely skips the intended fallback to legacy shared interrupts at
the use_intx label. Could this unnecessarily fail to initialize the device
on systems where MSI-X is unavailable?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260824113618.2239100-1-runyu.xiao@seu.edu.cn?part=1
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] scsi: pm8001: use rollback index when freeing MSI-X vectors
2026-08-24 11:36 [PATCH] scsi: pm8001: use rollback index when freeing MSI-X vectors Runyu Xiao
2026-08-24 11:53 ` sashiko-bot
@ 2026-08-28 11:30 ` Jinpu Wang
2026-08-29 1:36 ` Martin K. Petersen (Oracle)
2026-09-03 3:10 ` Martin K. Petersen (Oracle)
3 siblings, 0 replies; 5+ messages in thread
From: Jinpu Wang @ 2026-08-28 11:30 UTC (permalink / raw)
To: Runyu Xiao
Cc: James E . J . Bottomley, Martin K . Petersen, linux-scsi,
linux-kernel, stable, Jianhao Xu
On Mon, Aug 24, 2026 at 1:36 PM Runyu Xiao <runyu.xiao@seu.edu.cn> wrote:
>
> pm8001_request_msix() unwinds previously registered handlers with
> free_irq() when request_irq() fails. The rollback loop uses the
> failing index i for every iteration instead of the already
> registered vector index j.
>
> That passes the wrong IRQ/dev_id pair to free_irq() and leaves the
> earlier handlers installed. Use j for both pci_irq_vector() and the
> matching irq_vector entry in the rollback loop.
>
> Fixes: a76037ff3479 ("scsi: pm8001: switch to pci_irq_alloc_vectors")
> Cc: stable@vger.kernel.org
> Assisted-by: Codex:GPT-5
> Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> ---
> drivers/scsi/pm8001/pm8001_init.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index e93ea76b565e..21419e46c16d 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -1029,8 +1029,8 @@ static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha)
> &(pm8001_ha->irq_vector[i]));
> if (rc) {
> for (j = 0; j < i; j++) {
> - free_irq(pci_irq_vector(pm8001_ha->pdev, i),
> - &(pm8001_ha->irq_vector[i]));
> + free_irq(pci_irq_vector(pm8001_ha->pdev, j),
> + &pm8001_ha->irq_vector[j]);
> }
> pci_free_irq_vectors(pm8001_ha->pdev);
> break;
> --
> 2.34.1
^ permalink raw reply [flat|nested] 5+ messages in thread