CVE-2026-97502

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.