In the Linux kernel, the following vulnerability has been resolved:
mmc: mmci: stm32: fix DMA API overlapping mappings warning
Turning on CONFIG_DMA_API_DEBUG_SG results in the following warning:
DMA-API: mmci-pl18x 48220000.mmc: cacheline tracking EEXIST, overlapping mappings aren't supported WARNING: CPU: 1 PID: 51 at kernel/dma/debug.c:568 add_dma_entry+0x234/0x2f4 Modules linked in: CPU: 1 PID: 51 Comm: kworker/1:2 Not tainted 6.1.28 #1 Hardware name: STMicroelectronics STM32MP257F-EV1 Evaluation Board (DT) Workqueue: events_freezable mmc_rescan Call trace: add_dma_entry+0x234/0x2f4 debug_dma_map_sg+0x198/0x350 __dma_map_sg_attrs+0xa0/0x110 dma_map_sg_attrs+0x10/0x2c sdmmc_idma_prep_data+0x80/0xc0 mmci_prep_data+0x38/0x84 mmci_start_data+0x108/0x2dc mmci_request+0xe4/0x190 __mmc_start_request+0x68/0x140 mmc_start_request+0x94/0xc0 mmc_wait_for_req+0x70/0x100 mmc_send_tuning+0x108/0x1ac sdmmc_execute_tuning+0x14c/0x210 mmc_execute_tuning+0x48/0xec mmc_sd_init_uhs_card.part.0+0x208/0x464 mmc_sd_init_card+0x318/0x89c mmc_attach_sd+0xe4/0x180 mmc_rescan+0x244/0x320
DMA API debug brings to light leaking dma-mappings as dma_map_sg and dma_unmap_sg are not correctly balanced.
If an error occurs in mmci_cmd_irq function, only mmci_dma_error function is called and as this API is not managed on stm32 variant, dma_unmap_sg is never called in this error path.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:H5.5/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H