Description
In the Linux kernel, the following vulnerability has been resolved: blk-wbt: remove WARN_ON_ONCE from wbt_init_enable_default() wbt_init_enable_default() uses WARN_ON_ONCE to check for failures from wbt_alloc() and wbt_init(). However, both are expected failure paths: - wbt_alloc() can return NULL under memory pressure (-ENOMEM) - wbt_init() can fail with -EBUSY if wbt is already registered syzbot triggers this by injecting memory allocation failures during MTD partition creation via ioctl(BLKPG), causing a spurious warning. wbt_init_enable_default() is a best-effort initialization called from blk_register_queue() with a void return type. Failure simply means the disk operates without writeback throttling, which is harmless. Replace WARN_ON_ONCE with plain if-checks, consistent with how wbt_set_lat() in the same file already handles these failures. Add a pr_warn() for the wbt_init() failure to retain diagnostic information without triggering a full stack trace.
Product status
41afaeeda5099d9cd07eaa7dc6c3d20c6f1dd9e9 (git) before fd7a982657077469802594a5165bc30b9a55af70
41afaeeda5099d9cd07eaa7dc6c3d20c6f1dd9e9 (git) before e9b004ff83067cdf96774b45aea4b239ace99a2f
7.0
Any version before 7.0
7.0.10 (semver)
7.1 (original_commit_for_fix)
References
git.kernel.org/...c/fd7a982657077469802594a5165bc30b9a55af70
git.kernel.org/...c/e9b004ff83067cdf96774b45aea4b239ace99a2f