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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-11-06 17:25:36 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-11-21 16:15:42 -0300 |
| commit | 9c96c87d60eafa4d78406e606e92b42bd4b570ad (patch) | |
| tree | f2b1db62e65cdf8cae4e058bea8e40aae847dc16 /scripts | |
| parent | a72a4eb10b2d9aef7a53f9d2facf166a685d85fb (diff) | |
| download | glibc-9c96c87d60eafa4d78406e606e92b42bd4b570ad.tar.gz glibc-9c96c87d60eafa4d78406e606e92b42bd4b570ad.tar.xz glibc-9c96c87d60eafa4d78406e606e92b42bd4b570ad.zip | |
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 <siddhesh@sourceware.org> Reviewed-by: DJ Delorie <dj@redhat.com>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/gen-tunables.awk | 18 |
1 files changed, 2 insertions, 16 deletions
diff --git a/scripts/gen-tunables.awk b/scripts/gen-tunables.awk index d6de100df0..1e9d6b534e 100644 --- a/scripts/gen-tunables.awk +++ b/scripts/gen-tunables.awk @@ -61,9 +61,6 @@ $1 == "}" { if (!env_alias[top_ns,ns,tunable]) { env_alias[top_ns,ns,tunable] = "{0}" } - if (!security_level[top_ns,ns,tunable]) { - security_level[top_ns,ns,tunable] = "SXID_ERASE" - } len = length(top_ns"."ns"."tunable) if (len > max_name_len) max_name_len = len @@ -118,17 +115,6 @@ $1 == "}" { if (len > max_alias_len) max_alias_len = len } - else if (attr == "security_level") { - if (val == "SXID_ERASE" || val == "SXID_IGNORE" || val == "NONE") { - security_level[top_ns,ns,tunable] = val - } - else { - printf("Line %d: Invalid value (%s) for security_level: %s, ", NR, val, - $0) - print("Allowed values are 'SXID_ERASE', 'SXID_IGNORE', or 'NONE'") - exit 1 - } - } else if (attr == "default") { if (types[top_ns,ns,tunable] == "STRING") { default_val[top_ns,ns,tunable] = sprintf(".strval = \"%s\"", val); @@ -177,9 +163,9 @@ END { n = indices[2]; m = indices[3]; printf (" {TUNABLE_NAME_S(%s, %s, %s)", t, n, m) - printf (", {TUNABLE_TYPE_%s, %s, %s}, {%s}, false, TUNABLE_SECLEVEL_%s, %s},\n", + printf (", {TUNABLE_TYPE_%s, %s, %s}, {%s}, false, %s},\n", types[t,n,m], minvals[t,n,m], maxvals[t,n,m], - default_val[t,n,m], security_level[t,n,m], env_alias[t,n,m]); + default_val[t,n,m], env_alias[t,n,m]); } print "};" print "#endif" |