Reject CancelRequestPacket having unexpected length.
When the length was too short, the server read outside the allocation.
That yielded the same log noise as sending the correct length with
(backendPID,cancelAuthCode) matching nothing. Change to a message about
the unexpected length. Given the attacker's lack of control over the
memory layout and the general lack of diversity in memory layouts at the
code in question, we doubt a would-be attacker could cause a segfault.
Hence, while the report arrived via security@postgresql.org, this is not
a vulnerability. Back-patch to v11 (all supported versions).
Andrey Borodin, reviewed by Tom Lane. Reported by Andrey Borodin.
Branch
------
REL_11_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/8f70de7e0106dc0df8b31994e2b3ad06691f5836
Modified Files
--------------
src/backend/postmaster/postmaster.c | 7 +++++++
1 file changed, 7 insertions(+)