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scsi: ufs: ufs-qcom: Fix ESI null pointer dereference 

ESI/MSI is a performance optimization feature that provides dedicated
interrupts per MCQ hardware queue. This is optional feature and UFS MCQ
should work with and without ESI feature.

Commit e46a28cea2 ("scsi: ufs: qcom: Remove the MSI descriptor abuse")
brings a regression in ESI (Enhanced System Interrupt) configuration that
causes a null pointer dereference when Platform MSI allocation fails.

The issue occurs in when platform_device_msi_init_and_alloc_irqs() in
ufs_qcom_config_esi() fails (returns -EINVAL) but the current code uses
__free() macro for automatic cleanup free MSI resources that were never
successfully allocated.

Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000008

  Call trace:
  mutex_lock+0xc/0x54 (P)
  platform_device_msi_free_irqs_all+0x1c/0x40
  ufs_qcom_config_esi+0x1d0/0x220 [ufs_qcom]
  ufshcd_config_mcq+0x28/0x104
  ufshcd_init+0xa3c/0xf40
  ufshcd_pltfrm_init+0x504/0x7d4
  ufs_qcom_probe+0x20/0x58 [ufs_qcom]

Fix by restructuring the ESI configuration to try MSI allocation first,
before any other resource allocation and instead use explicit cleanup
instead of __free() macro to avoid cleanup of unallocated resources.

Tested on SM8750 platform with MCQ enabled, both with and without
Platform ESI support.

Fixes: e46a28cea2 ("scsi: ufs: qcom: Remove the MSI descriptor abuse")
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
Link: https://lore.kernel.org/r/20250811073330.20230-1-quic_nitirawa@quicinc.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
pull/1322/head
Nitin Rawat 2025-08-11 13:03:30 +05:30 committed by Martin K. Petersen
parent 09d57d68ba
commit 6300d5c543
1 changed files with 15 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/ufs/host/ufs-qcom.c
View File

@ -2070,17 +2070,6 @@ static irqreturn_t ufs_qcom_mcq_esi_handler(int irq, void *data)
return IRQ_HANDLED;
}
static void ufs_qcom_irq_free(struct ufs_qcom_irq *uqi)
{
for (struct ufs_qcom_irq *q = uqi; q->irq; q++)
devm_free_irq(q->hba->dev, q->irq, q->hba);
platform_device_msi_free_irqs_all(uqi->hba->dev);
devm_kfree(uqi->hba->dev, uqi);
}
DEFINE_FREE(ufs_qcom_irq, struct ufs_qcom_irq *, if (_T) ufs_qcom_irq_free(_T))
static int ufs_qcom_config_esi(struct ufs_hba *hba)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
@ -2095,18 +2084,18 @@ static int ufs_qcom_config_esi(struct ufs_hba *hba)
*/
nr_irqs = hba->nr_hw_queues - hba->nr_queues[HCTX_TYPE_POLL];
struct ufs_qcom_irq *qi __free(ufs_qcom_irq) =
devm_kcalloc(hba->dev, nr_irqs, sizeof(*qi), GFP_KERNEL);
if (!qi)
return -ENOMEM;
/* Preset so __free() has a pointer to hba in all error paths */
qi[0].hba = hba;
ret = platform_device_msi_init_and_alloc_irqs(hba->dev, nr_irqs,
ufs_qcom_write_msi_msg);
if (ret) {
dev_err(hba->dev, "Failed to request Platform MSI %d\n", ret);
return ret;
dev_warn(hba->dev, "Platform MSI not supported or failed, continuing without ESI\n");
return ret; /* Continue without ESI */
}
struct ufs_qcom_irq *qi = devm_kcalloc(hba->dev, nr_irqs, sizeof(*qi), GFP_KERNEL);
if (!qi) {
platform_device_msi_free_irqs_all(hba->dev);
return -ENOMEM;
}
for (int idx = 0; idx < nr_irqs; idx++) {
@ -2117,15 +2106,17 @@ static int ufs_qcom_config_esi(struct ufs_hba *hba)
ret = devm_request_irq(hba->dev, qi[idx].irq, ufs_qcom_mcq_esi_handler,
IRQF_SHARED, "qcom-mcq-esi", qi + idx);
if (ret) {
dev_err(hba->dev, "%s: Fail to request IRQ for %d, err = %d\n",
dev_err(hba->dev, "%s: Failed to request IRQ for %d, err = %d\n",
__func__, qi[idx].irq, ret);
qi[idx].irq = 0;
/* Free previously allocated IRQs */
for (int j = 0; j < idx; j++)
devm_free_irq(hba->dev, qi[j].irq, qi + j);
platform_device_msi_free_irqs_all(hba->dev);
devm_kfree(hba->dev, qi);
return ret;
}
}
retain_and_null_ptr(qi);
if (host->hw_ver.major >= 6) {
ufshcd_rmwl(hba, ESI_VEC_MASK, FIELD_PREP(ESI_VEC_MASK, MAX_ESI_VEC - 1),
REG_UFS_CFG3);