In the Linux kernel, the following vulnerability has been resolved:
tcp: add sanity checks to rx zerocopy
TCP rx zerocopy intent is to map pages initially allocated
from NIC drivers, not pages owned by a fs.
This patch adds to can_map_frag() these additional checks:
- Page must not be a compound one.
- page->mapping must be NULL.
This fixes the panic reported by ZhangPeng.
syzbot was able to ...