CVEvulnerability
CVE-2026-80698
- Status
- Received
- Published
- 2026-08-28
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: fix double free of wq, engine, and group structs
The release callbacks for wq, engine, and group devices
(idxd_conf_wq_release, idxd_conf_engine_release,
idxd_conf_group_release) each call kfree() on the enclosing struct.
The setup error paths and cleanup functions also call kfree()
explicitly after put_device(), producing a double free whenever
put_device() drops the reference count to zero and fires the release.
In the setup functions, device_initialize() is called before
device_add(), so the reference count is exactly 1 at the error sites.
put_device() unconditionally fires the release, which frees the struct;
the subsequent explicit kfree() then operates on freed memory.
For idxd_setup_wqs(), the wq release callback also owns opcap_bmap
and wqcfg. The error unwind additionally freed those fields explicitly
before calling put_device(), causing further double frees on both.
Remove the redundant explicit kfree() calls from all setup error paths
and cleanup functions for wq, engine, and group structs, delegating
sole ownership of those allocations to the release callbacks.
References
- https://git.kernel.org/stable/c/38208445c41a6164e26748c600f954296991364d git.kernel.org
- https://git.kernel.org/stable/c/63844dc03960b09b36746eda636c08f1479407ce git.kernel.org
- https://git.kernel.org/stable/c/84cf00b1376c717e55d704dc259483e822ae1b34 git.kernel.org
- https://git.kernel.org/stable/c/c93a9f652b7373ac8ee5bfcc18a9af76959b6c6c git.kernel.org
- https://git.kernel.org/stable/c/ec2d428b2e32dd157de8f86a86dd85c5b2c8f45c git.kernel.org