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CVE-2026-97502

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

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.16%Chance of exploitation activity in the next 30 days, higher than 4% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in51738de7dd5f8e8b33dfc07ef85bc06d3bf41e96Also 3c5e3e5badbf0592332887d12db02458323682c3, 5b7e151fe9ea9311ba601849aaecdc4fc97fd577 and 1 moreCVE List
Published24 Sep 2026Updated 3 Oct 2026CVE List

What fixes it

  • 51738de7dd5f8e8b33dfc07ef85bc06d3bf41e96LinuxCVE List
  • 3c5e3e5badbf0592332887d12db02458323682c3LinuxCVE List
  • 5b7e151fe9ea9311ba601849aaecdc4fc97fd577LinuxCVE List
  • 4f28846aaf8db9668e338b8987973f8935edff34LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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.

Text from CVE List

Affected versions 16

  • Linuxaffected: b4cff4549b7a8c5fc8b88e3493b6287555f0512c before 51738de7dd5f8e8b33dfc07ef85bc06d3bf41e96CVE List
  • Linuxaffected: b4cff4549b7a8c5fc8b88e3493b6287555f0512c before f216cf00e829895ff49bdf695c944915e59bd698CVE List
  • Linuxaffected: b4cff4549b7a8c5fc8b88e3493b6287555f0512c before a0cde8d70d64c1a75fbd57f01d9f2d7cccac8319CVE List
  • Linuxaffected: b4cff4549b7a8c5fc8b88e3493b6287555f0512c before 3c5e3e5badbf0592332887d12db02458323682c3CVE List
  • Linuxaffected: b4cff4549b7a8c5fc8b88e3493b6287555f0512c before a01cedf230dc0fcd55b994f5e548d3982ba4c732CVE List
  • Linuxaffected: b4cff4549b7a8c5fc8b88e3493b6287555f0512c before 5b7e151fe9ea9311ba601849aaecdc4fc97fd577CVE List
  • Linuxaffected: b4cff4549b7a8c5fc8b88e3493b6287555f0512c before 4f28846aaf8db9668e338b8987973f8935edff34CVE List
  • Linuxaffected: 2.6.33CVE List
  • Linuxunaffected: all versions before 2.6.33CVE List
  • Linuxunaffected: 5.10.271 through 5.10.*CVE List
  • Linuxunaffected: 5.15.222 through 5.15.*CVE List
  • Linuxunaffected: 6.1.189 through 6.1.*CVE List
  • Linuxunaffected: 6.6.158 through 6.6.*CVE List
  • Linuxunaffected: 6.12.111 through 6.12.*CVE List
  • Linuxunaffected: 6.18.53 through 6.18.*CVE List
  • Linuxunaffected: 7.2CVE List

References 7