Security related changes:
- [Add security related changes here]
+ CVE-2019-19126: ld.so failed to ignore the LD_PREFER_MAP_32BIT_EXEC
+ environment variable during program execution after a security
+ transition, allowing local attackers to restrict the possible mapping
+ addresses for loaded libraries and thus bypass ASLR for a setuid
+ program. Reported by Marcin Kościelnicki.
The following bugs are resolved with this release:
environment variable, LD_PREFER_MAP_32BIT_EXEC. */
#define EXTRA_LD_ENVVARS \
case 21: \
- if (memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0) \
+ if (!__libc_enable_secure \
+ && memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0) \
GLRO(dl_x86_cpu_features).feature[index_arch_Prefer_MAP_32BIT_EXEC] \
|= bit_arch_Prefer_MAP_32BIT_EXEC; \
break;