CVE-2026-31467

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 vmmapram() with GFP_KERNEL.

Due to insufficient memory, vmmapram() may generate memory swapping I/O, which can cause submitbiowait to deadlock in some scenarios.

Trimmed down the call stack, as follows:

f2fssubmitreadio submitbio //biolist is initialized. mmcblkmqrecovery zerofsendio vmmapram __pteallockernel __allocpagesdirectreclaim shrinkfolio_list __swapwritepage submitbiowait //biolist is non-NULL, hang!!!

Use memallocnoio{save,restore}() to wrap up this path.