CVE-2026-72257 ASoC: qcom: q6apm: fix NULL pointer dereference in graph_callback
A race condition in the Qualcomm ASoC driver causes a NULL pointer dereference, leading to a kernel crash and denial of service.
- 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-2026-72257?
CVE-2026-72257 is a vulnerability in Linux, published on 15 Aug 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:
ASoC: qcom: q6apm: fix NULL pointer dereference in graph_callback
When q6apm_free_fragments() is called it frees rx_data.buf/tx_data.buf and sets them to NULL under graph->lock. A late DSP buffer-done response can race with this: graph_callback() passes the !graph->ar_graph guard (not yet NULL), acquires the lock, but then dereferences a now-NULL buf pointer to read buf[token].phys, crashing at virtual address 0x10.
Add a NULL check for buf inside the mutex-protected section in both the write-done (DATA_CMD_RSP_WR_SH_MEM_EP_DATA_BUFFER_DONE_V2) and read-done (DATA_CMD_RSP_RD_SH_MEM_EP_DATA_BUFFER_V2) handlers and bail out cleanly if buffers have already been freed.
This problem is only shown up recently while apr bus was updated to process the commands per service rather from single global queue.
Which versions are affected by CVE-2026-72257?
How do I fix CVE-2026-72257?
Apply the vendor's patch.
Is CVE-2026-72257 being exploited?
There is no known exploitation of CVE-2026-72257 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72257, DEBIAN-CVE-2026-72257, GHSA-jf3h-8vwv-gqw3, UBUNTU-CVE-2026-72257.