CVE-2026-31467 erofs: add GFP_NOIO in the bio completion if needed
A deadlock in the Linux kernel's EROFS filesystem can cause a denial of service when memory pressure triggers swapping during bio completion.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31467?
CVE-2026-31467 is a high-severity denial of service vulnerability in Linux kernel, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
erofs: add GFP_NOIO in the bio completion if needed
The bio completion path in the process context (e.g. dm-verity) will directly call into decompression rather than trigger another workqueue context for minimal scheduling latencies, which can then call vm_map_ram() with GFP_KERNEL.
Due to insufficient memory, vm_map_ram() may generate memory swapping I/O, which can cause submit_bio_wait to deadlock in some scenarios.
Trimmed down the call stack, as follows:
f2fs_submit_read_io submit_bio //bio_list is initialized. mmc_blk_mq_recovery z_erofs_endio vm_map_ram __pte_alloc_kernel __alloc_pages_direct_reclaim shrink_folio_list __swap_writepage submit_bio_wait //bio_list is non-NULL, hang!!!
Use memalloc_noio_{save,restore}() to wrap up this path.
Weakness: CWE-667
Which versions are affected by CVE-2026-31467?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31467?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-31467 being exploited?
There is no known exploitation of CVE-2026-31467 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-83363, BELL-CVE-2026-31467, DEBIAN-CVE-2026-31467, GHSA-v4fx-vwm3-3682, ROOT-OS-DEBIAN-11-CVE-2026-31467, ROOT-OS-DEBIAN-12-CVE-2026-31467 and 4 more.