ring-buffer: Check resize_disabled before publishing the new subbuf order
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 91% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Check resize_disabled before publishing the new subbuf order
ring_buffer_subbuf_order_set() stores the new order and only then walks
the CPUs, returning -EBUSY if any of them has resizing disabled. A user
mapped buffer has resizing disabled, and __rb_map_vma() reads
buffer->subbuf_order without buffer->mutex, so an mmap of an already
mapped CPU racing the failing order change sizes the mapping with the
new order and inserts pages past the sub-buffer into the VMA.
Check the CPUs before storing the new order.
Affected products
Linux · Linux