IT

Tracker / CVE-2022-50530

CVE-2022-50530

Medium 5.5

In the Linux kernel, the following vulnerability has been resolved: blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping() Our syzkaller report a null pointer dereference, root cause is following: __blk_mq_alloc_map_and_rqs set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs blk_mq_alloc_map_and_rqs blk_mq_alloc_rqs // failed due to oom alloc_pages_node // set->tags[hctx_idx] is still NULL blk_mq_free_rqs drv_tags = set->tags[hctx_idx]; // null pointer dereference is triggered blk_mq_clear_rq_mapping(drv_tags, ...) This is because commit 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()") merged the two steps: 1) set->tags[hctx_idx] = blk_mq_alloc_rq_map() 2) blk_mq_alloc_rqs(..., set->tags[hctx_idx]) into one step: set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs() Since tags is not initialized yet in this case, fix the problem by checking if tags is NULL pointer in blk_mq_clear_rq_mapping().

Affected products and versions

linux linux_kernel
linux linux_kernel · 5.16 → 6.0.6

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References