diff options
Diffstat (limited to 'patches/source/glibc/glibc.46703a39.diff')
| -rw-r--r-- | patches/source/glibc/glibc.46703a39.diff | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/patches/source/glibc/glibc.46703a39.diff b/patches/source/glibc/glibc.46703a39.diff new file mode 100644 index 00000000..c21200be --- /dev/null +++ b/patches/source/glibc/glibc.46703a39.diff @@ -0,0 +1,119 @@ +From 46703a3995aa3ca2b816814aa4ad05ed524194dd Mon Sep 17 00:00:00 2001 +From: Florian Weimer <fweimer@redhat.com> +Date: Mon, 19 Jun 2017 22:31:04 +0200 +Subject: [PATCH] ld.so: Reject overly long LD_PRELOAD path elements + +(cherry picked from commit 6d0ba622891bed9d8394eef1935add53003b12e8) + +diff --git a/elf/rtld.c b/elf/rtld.c +index 2fc33a6..4badcf6 100644 +--- a/elf/rtld.c ++++ b/elf/rtld.c +@@ -99,6 +99,35 @@ uintptr_t __pointer_chk_guard_local + strong_alias (__pointer_chk_guard_local, __pointer_chk_guard) + #endif + ++/* Length limits for names and paths, to protect the dynamic linker, ++ particularly when __libc_enable_secure is active. */ ++#ifdef NAME_MAX ++# define SECURE_NAME_LIMIT NAME_MAX ++#else ++# define SECURE_NAME_LIMIT 255 ++#endif ++#ifdef PATH_MAX ++# define SECURE_PATH_LIMIT PATH_MAX ++#else ++# define SECURE_PATH_LIMIT 1024 ++#endif ++ ++/* Check that AT_SECURE=0, or that the passed name does not contain ++ directories and is not overly long. Reject empty names ++ unconditionally. */ ++static bool ++dso_name_valid_for_suid (const char *p) ++{ ++ if (__glibc_unlikely (__libc_enable_secure)) ++ { ++ /* Ignore pathnames with directories for AT_SECURE=1 ++ programs, and also skip overlong names. */ ++ size_t len = strlen (p); ++ if (len >= SECURE_NAME_LIMIT || memchr (p, '/', len) != NULL) ++ return false; ++ } ++ return *p != '\0'; ++} + + /* List of auditing DSOs. */ + static struct audit_list +@@ -716,6 +745,42 @@ static const char *preloadlist attribute_relro; + /* Nonzero if information about versions has to be printed. */ + static int version_info attribute_relro; + ++/* The LD_PRELOAD environment variable gives list of libraries ++ separated by white space or colons that are loaded before the ++ executable's dependencies and prepended to the global scope list. ++ (If the binary is running setuid all elements containing a '/' are ++ ignored since it is insecure.) Return the number of preloads ++ performed. */ ++unsigned int ++handle_ld_preload (const char *preloadlist, struct link_map *main_map) ++{ ++ unsigned int npreloads = 0; ++ const char *p = preloadlist; ++ char fname[SECURE_PATH_LIMIT]; ++ ++ while (*p != '\0') ++ { ++ /* Split preload list at space/colon. */ ++ size_t len = strcspn (p, " :"); ++ if (len > 0 && len < sizeof (fname)) ++ { ++ memcpy (fname, p, len); ++ fname[len] = '\0'; ++ } ++ else ++ fname[0] = '\0'; ++ ++ /* Skip over the substring and the following delimiter. */ ++ p += len; ++ if (*p != '\0') ++ ++p; ++ ++ if (dso_name_valid_for_suid (fname)) ++ npreloads += do_preload (fname, main_map, "LD_PRELOAD"); ++ } ++ return npreloads; ++} ++ + static void + dl_main (const ElfW(Phdr) *phdr, + ElfW(Word) phnum, +@@ -1462,23 +1527,8 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n", + + if (__glibc_unlikely (preloadlist != NULL)) + { +- /* The LD_PRELOAD environment variable gives list of libraries +- separated by white space or colons that are loaded before the +- executable's dependencies and prepended to the global scope +- list. If the binary is running setuid all elements +- containing a '/' are ignored since it is insecure. */ +- char *list = strdupa (preloadlist); +- char *p; +- + HP_TIMING_NOW (start); +- +- /* Prevent optimizing strsep. Speed is not important here. */ +- while ((p = (strsep) (&list, " :")) != NULL) +- if (p[0] != '\0' +- && (__builtin_expect (! __libc_enable_secure, 1) +- || strchr (p, '/') == NULL)) +- npreloads += do_preload (p, main_map, "LD_PRELOAD"); +- ++ npreloads += handle_ld_preload (preloadlist, main_map); + HP_TIMING_NOW (stop); + HP_TIMING_DIFF (diff, start, stop); + HP_TIMING_ACCUM_NT (load_time, diff); +-- +2.9.3 + + |