{"id":"CVE-2026-72134","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-72134","summary":"spi: imx: reconfigure for PIO when DMA cannot be started","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nspi: imx: reconfigure for PIO when DMA cannot be started\n\nWhen spi_imx_can_dma() selects DMA, the ECSPI is configured for DMA:\nspi_imx_setupxfer() sets CTRL.SMC and clears dynamic_burst, and\nspi_imx_dma_transfer() programs the dynamic-burst BURST_LENGTH and the\nSDMA watermarks.\n\nIf the DMA descriptor cannot be prepared (dmaengine_prep_slave_single()\nreturns NULL), the transfer is failed with SPI_TRANS_FAIL_NO_START and\nfalls back to PIO. The dynamic-burst DMA path uses its own bounce\nbuffers instead of the SPI core's mapping, so xfer->{tx,rx}_sg_mapped\nare not set and the core's DMA->PIO retry is skipped; the driver falls\nback to PIO internally. But none of the DMA-mode configuration is\nundone, so the PIO transfer runs with CTRL.SMC set, the wrong burst\nlength and dynamic_burst cleared, and the transferred data is corrupted.\n\nThis is easily hit on i.MX8MP boards that describe ECSPI DMA in the\ndevice tree but run SDMA on ROM firmware (no external sdma-imx7d.bin):\nevery ECSPI DMA prepare fails. An Infineon SLB9670 TPM on ECSPI1 then\nreturns shifted TPM2_GetCapability data, is flagged \"field failure\nmode\", /dev/tpmrm0 is never created.\n\nSet controller->fallback before re-running spi_imx_setupxfer() so the\nECSPI is reconfigured exactly like a normal PIO transfer. With\ncontroller->fallback set, spi_imx_setupxfer() sees spi_imx_can_dma()\nreturn false, so it clears spi_imx->usedma and reprograms the controller\n(clears CTRL.SMC, restores dynamic_burst and the PIO burst length). No\nexplicit spi_imx->usedma = false is needed: setupxfer() already updates\nit from the can_dma() result.","published":"2026-08-15T05:53:09.573Z","modified":"2026-08-18T03:56:21.250153082Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"7.1.5"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/245404c26563aafb36aafb01298f148db1851be3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/40dee2d3e9994aed9efe7bed40eb0e4d38d5a25c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72134.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72134"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:21.250153082Z"}}