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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-07-24 06:06:08 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-07-24 06:06:24 -0700 |
| commit | 422ff87c249ddc06701d096421db63343e4754be (patch) | |
| tree | e095970d350bffebdd21f9fa75a24494aeebbc47 | |
| parent | 55703fcace89b53d7f41f7d85ede50571da2bcc8 (diff) | |
| download | glibc-422ff87c249ddc06701d096421db63343e4754be.tar.gz glibc-422ff87c249ddc06701d096421db63343e4754be.tar.xz glibc-422ff87c249ddc06701d096421db63343e4754be.zip | |
Avoid accessing corrupted stack from __stack_chk_fail [BZ #21752]
__libc_argv[0] points to address on stack and __libc_secure_getenv accesses environment variables which are on stack. We should avoid accessing stack when stack is corrupted. This patch also renames function argument in __fortify_fail_abort from do_backtrace to need_backtrace to avoid confusion with do_backtrace from enum __libc_message_action. [BZ #21752] * debug/fortify_fail.c (__fortify_fail_abort): Don't pass down __libc_argv[0] if we aren't doing backtrace. Rename do_backtrace to need_backtrace. * sysdeps/posix/libc_fatal.c (__libc_message): Don't call __libc_secure_getenv if we aren't doing backtrace.
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | debug/fortify_fail.c | 12 | ||||
| -rw-r--r-- | sysdeps/posix/libc_fatal.c | 15 |
3 files changed, 27 insertions, 9 deletions
diff --git a/ChangeLog b/ChangeLog index 6f1fb54730..7da4510060 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2017-07-24 H.J. Lu <hongjiu.lu@intel.com> + + [BZ #21752] + * debug/fortify_fail.c (__fortify_fail_abort): Don't pass down + __libc_argv[0] if we aren't doing backtrace. Rename do_backtrace + to need_backtrace. + * sysdeps/posix/libc_fatal.c (__libc_message): Don't call + __libc_secure_getenv if we aren't doing backtrace. + 2017-07-24 Andreas Schwab <schwab@suse.de> [BZ #21804] diff --git a/debug/fortify_fail.c b/debug/fortify_fail.c index c90d384daf..a0777ae570 100644 --- a/debug/fortify_fail.c +++ b/debug/fortify_fail.c @@ -24,13 +24,17 @@ extern char **__libc_argv attribute_hidden; void __attribute__ ((noreturn)) internal_function -__fortify_fail_abort (_Bool do_backtrace, const char *msg) +__fortify_fail_abort (_Bool need_backtrace, const char *msg) { - /* The loop is added only to keep gcc happy. */ + /* The loop is added only to keep gcc happy. Don't pass down + __libc_argv[0] if we aren't doing backtrace since __libc_argv[0] + may point to the corrupted stack. */ while (1) - __libc_message (do_backtrace ? (do_abort | do_backtrace) : do_abort, + __libc_message (need_backtrace ? (do_abort | do_backtrace) : do_abort, "*** %s ***: %s terminated\n", - msg, __libc_argv[0] ?: "<unknown>"); + msg, + (need_backtrace && __libc_argv[0] != NULL + ? __libc_argv[0] : "<unknown>")); } void diff --git a/sysdeps/posix/libc_fatal.c b/sysdeps/posix/libc_fatal.c index 25af8bd413..c9189194dd 100644 --- a/sysdeps/posix/libc_fatal.c +++ b/sysdeps/posix/libc_fatal.c @@ -75,11 +75,16 @@ __libc_message (enum __libc_message_action action, const char *fmt, ...) FATAL_PREPARE; #endif - /* Open a descriptor for /dev/tty unless the user explicitly - requests errors on standard error. */ - const char *on_2 = __libc_secure_getenv ("LIBC_FATAL_STDERR_"); - if (on_2 == NULL || *on_2 == '\0') - fd = open_not_cancel_2 (_PATH_TTY, O_RDWR | O_NOCTTY | O_NDELAY); + /* Don't call __libc_secure_getenv if we aren't doing backtrace, which + may access the corrupted stack. */ + if ((action & do_backtrace)) + { + /* Open a descriptor for /dev/tty unless the user explicitly + requests errors on standard error. */ + const char *on_2 = __libc_secure_getenv ("LIBC_FATAL_STDERR_"); + if (on_2 == NULL || *on_2 == '\0') + fd = open_not_cancel_2 (_PATH_TTY, O_RDWR | O_NOCTTY | O_NDELAY); + } if (fd == -1) fd = STDERR_FILENO; |