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>
6300d5c543