CVE-2026-98677 iio: adc: ad_sigma_delta: fix use-after-free on unbind
A use-after-free in the Linux kernel AD Sigma-Delta ADC driver allows attackers to execute code or cause a denial of service via device unbinding.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98677?
CVE-2026-98677 is an use after free vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
iio: adc: ad_sigma_delta: fix use-after-free on unbind
ad_sd_buffer_postenable() allocates sigma_delta->samples_buf with devm_krealloc() at runtime, so its devres entry sits after all probe-time entries of the driver. devm resources are released in reverse allocation order, which means unbind frees samples_buf before iio_device_unregister() disables the buffers and detaches the trigger pollfunc. The data ready IRQ is still enabled at that point, so ad_sd_trigger_handler() can still run and memcpy() incoming samples into the freed samples_buf.
Fix this by preallocating the buffer in devm_ad_sd_setup_buffer_and_trigger(), before the triggered buffer and the IRQ are set up, so it is freed only after iio_device_unregister() has drained the trigger handler via free_irq(). Size it for the worst case of all sequencer slots being active; ad_sd_validate_scan_mask() already caps the number of active channels at num_slots.
This issue was found by an in-house static analysis tool.
Which versions are affected by CVE-2026-98677?
How do I fix CVE-2026-98677?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-98677 being exploited?
There is no known exploitation of CVE-2026-98677 in the wild and no public exploit code.
Sources
Also known as AZL-108731, BELL-CVE-2026-98677, DEBIAN-CVE-2026-98677, GHSA-852j-fqfh-mmqj, UBUNTU-CVE-2026-98677.