From 9c96c87d60eafa4d78406e606e92b42bd4b570ad Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 6 Nov 2023 17:25:36 -0300 Subject: elf: Ignore GLIBC_TUNABLES for setuid/setgid binaries The tunable privilege levels were a retrofit to try and keep the malloc tunable environment variables' behavior unchanged across security boundaries. However, CVE-2023-4911 shows how tricky can be tunable parsing in a security-sensitive environment. Not only parsing, but the malloc tunable essentially changes some semantics on setuid/setgid processes. Although it is not a direct security issue, allowing users to change setuid/setgid semantics is not a good security practice, and requires extra code and analysis to check if each tunable is safe to use on all security boundaries. It also means that security opt-in features, like aarch64 MTE, would need to be explicit enabled by an administrator with a wrapper script or with a possible future system-wide tunable setting. Co-authored-by: Siddhesh Poyarekar Reviewed-by: DJ Delorie --- sysdeps/x86_64/64/dl-tunables.list | 1 - 1 file changed, 1 deletion(-) (limited to 'sysdeps/x86_64') diff --git a/sysdeps/x86_64/64/dl-tunables.list b/sysdeps/x86_64/64/dl-tunables.list index 0aab52e..54a216a 100644 --- a/sysdeps/x86_64/64/dl-tunables.list +++ b/sysdeps/x86_64/64/dl-tunables.list @@ -23,7 +23,6 @@ glibc { minval: 0 maxval: 1 env_alias: LD_PREFER_MAP_32BIT_EXEC - security_level: SXID_IGNORE } } } -- cgit v1.1