From 6c6fce572fb8f583f14d898e54fd7d25ae91cf56 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 6 Nov 2023 17:25:34 -0300 Subject: elf: Remove /etc/suid-debug support Since malloc debug support moved to a different library (libc_malloc_debug.so), the glibc.malloc.check requires preloading the debug library to enable it. It means that suid-debug support has not been working since 2.34. To restore its support, it would require to add additional information and parsing to where to find libc_malloc_debug.so. It is one thing less that might change AT_SECURE binaries' behavior due to environment configurations. Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar --- elf/dl-tunables.c | 16 ---------------- elf/rtld.c | 3 +-- 2 files changed, 1 insertion(+), 18 deletions(-) (limited to 'elf') diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index cae67ef..24252af 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -252,20 +252,6 @@ parse_tunables (char *tunestr, char *valstring) tunestr[off] = '\0'; } -/* Enable the glibc.malloc.check tunable in SETUID/SETGID programs only when - the system administrator has created the /etc/suid-debug file. This is a - special case where we want to conditionally enable/disable a tunable even - for setuid binaries. We use the special version of access() to avoid - setting ERRNO, which is a TLS variable since TLS has not yet been set - up. */ -static __always_inline void -maybe_enable_malloc_check (void) -{ - tunable_id_t id = TUNABLE_ENUM_NAME (glibc, malloc, check); - if (__libc_enable_secure && __access_noerrno ("/etc/suid-debug", F_OK) == 0) - tunable_list[id].security_level = TUNABLE_SECLEVEL_NONE; -} - /* Initialize the tunables list from the environment. For now we only use the ENV_ALIAS to find values. Later we will also use the tunable names to find values. */ @@ -277,8 +263,6 @@ __tunables_init (char **envp) size_t len = 0; char **prev_envp = envp; - maybe_enable_malloc_check (); - while ((envp = get_next_env (envp, &envname, &len, &envval, &prev_envp)) != NULL) { diff --git a/elf/rtld.c b/elf/rtld.c index 5107d16..51b6d9f 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -2670,8 +2670,7 @@ process_envvars (struct dl_main_state *state) } while (*nextp != '\0'); - if (__access ("/etc/suid-debug", F_OK) != 0) - GLRO(dl_debug_mask) = 0; + GLRO(dl_debug_mask) = 0; if (state->mode != rtld_mode_normal) _exit (5); -- cgit v1.1