From 09d4d603603aeab26e57721b3fbae504dab5284e Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 18 Mar 2022 11:49:05 +0100 Subject: [PATCH] doc: mention that setfsuid() is a reason why UIDs >= 2147483648 are icky --- docs/UIDS-GIDS.md | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/docs/UIDS-GIDS.md b/docs/UIDS-GIDS.md index 6931536185..e90d6f0596 100644 --- a/docs/UIDS-GIDS.md +++ b/docs/UIDS-GIDS.md @@ -283,11 +283,12 @@ pre-defined purposes between Linux, generic low-level distributions and ranges. Note that the range 2147483648…4294967294 (i.e. 2^31…2^32-2) should be handled -with care. Various programs (including kernel file systems, see `devpts`) have -trouble with UIDs outside of the signed 32bit range, i.e any UIDs equal to or -above 2147483648. It is thus strongly recommended to stay away from this range -in order to avoid complications. This range should be considered reserved for -future, special purposes. +with care. Various programs (including kernel file systems — see `devpts` — or +even kernel syscalls – see `setfsuid()`) have trouble with UIDs outside of the +signed 32bit range, i.e any UIDs equal to or above 2147483648. It is thus +strongly recommended to stay away from this range in order to avoid +complications. This range should be considered reserved for future, special +purposes. ## Notes on resolvability of user and group names -- 2.25.1