CVE-2026-97502

Summary

In the Linux kernel, the following vulnerability has been resolved:

mmc: davinci: avoid NULL deref of host->data in IRQ handler

mmc_davinci_irq() returns early only when both host->cmd and host->data are NULL:

if (host->cmd == NULL && host->data == NULL) { … return IRQ_NONE; }

So we may legitimately reach the rest of the handler with host->data == NULL (and therefore data == NULL). The DATDNE branch already guards against this with an explicit "if (data != NULL)" check, but the subsequent TOUTRD ("read data timeout") and CRCWR/CRCRD ("data CRC error") branches dereference data unconditionally:

if (qstatus & MMCST0_TOUTRD) { data->error = -ETIMEDOUT; <– NULL deref … davinci_abort_data(host, data); }

if (qstatus & (MMCST0_CRCWR | MMCST0_CRCRD)) { data->error = -EILSEQ; <– NULL deref … }

If either bit is set in qstatus while host->data is NULL, the kernel will crash inside the IRQ handler. smatch flags this:

drivers/mmc/host/davinci_mmc.c:933 mmc_davinci_irq() error: we previously assumed 'data' could be null (see line 914)

Gate both branches on a non-NULL data, matching the existing pattern used by the DATDNE branch.

No functional change for callers where data is non-NULL, which is the only case in which these branches did meaningful work before this change.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/a01cedf230dc0fcd55b994f5e548d3982ba4c732
• https://git.kernel.org/stable/c/5b7e151fe9ea9311ba601849aaecdc4fc97fd577
• https://git.kernel.org/stable/c/4f28846aaf8db9668e338b8987973f8935edff34

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