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 secur...@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_14_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/6900aea67e27990b72bc28b0b69096db9d226cba Modified Files -------------- src/backend/postmaster/postmaster.c | 7 +++++++ 1 file changed, 7 insertions(+)