vmalloc: fix buffer overflow in vrealloc_node_align()
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.1%
exploitation probability
0.1%top 96% of all CVEs
observed exploitation
nono source reports it
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 products
Linux · Linux