Skip to content
Commit 85eac2ba authored by Mateusz Jurczyk's avatar Mateusz Jurczyk Committed by David S. Miller
Browse files

decnet: dn_rtmsg: Improve input length sanitization in dnrmg_receive_user_skb



Verify that the length of the socket buffer is sufficient to cover the
entire nlh->nlmsg_len field before accessing that field for further
input sanitization. If the client only supplies 1-3 bytes of data in
sk_buff, then nlh->nlmsg_len remains partially uninitialized and
contains leftover memory from the corresponding kernel allocation.
Operating on such data may result in indeterminate evaluation of the
nlmsg_len < sizeof(*nlh) expression.

The bug was discovered by a runtime instrumentation designed to detect
use of uninitialized memory in the kernel. The patch prevents this and
other similar tools (e.g. KMSAN) from flagging this behavior in the future.

Signed-off-by: default avatarMateusz Jurczyk <mjurczyk@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ed66e50d
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment