CVE-2026-46281

Summary

In the Linux kernel, the following vulnerability has been resolved:

vmalloc: fix buffer overflow in vrealloc_node_align()

Commit 4c5d3365882d ("mm/vmalloc: allow to set node and align in vrealloc") added the ability to force a new allocation if the current pointer is on the wrong NUMA node, or if an alignment constraint is not met, even if the user is shrinking the allocation.

On this path (need_realloc), the code allocates a new object of 'size' bytes and then memcpy()s 'old_size' bytes into it. If the request is to shrink the object (size < old_size), this results in an out-of-bounds write on the new buffer.

Fix this by bounding the copy length by the new allocation size.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux4c5d3365882dbbc0784688784904f440d7a4c0f1 < e9b057a44deff4c59c13f44672a5cc74dcd57522affected
LinuxLinux4c5d3365882dbbc0784688784904f440d7a4c0f1 < b281adf71f786c325eb6d6d1582d4d05313438a8affected
LinuxLinux4c5d3365882dbbc0784688784904f440d7a4c0f1 < 82d1f01292d3f09bf063f829f8ab8de12b4280a1affected
LinuxLinux6.18affected
LinuxLinux0 < 6.18unaffected
LinuxLinux6.18.27 <= 6.18.*unaffected
LinuxLinux7.0.4 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References