Date: Tue, 28 Jan 2020 18:53:15 +0000 (UTC) From: Gordon Tetlow <gordon@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-releng@freebsd.org Subject: svn commit: r357215 - in releng: 11.3/lib/libc/secure 12.0/lib/libc/secure 12.1/lib/libc/secure Message-ID: <202001281853.00SIrF0T037601@repo.freebsd.org>
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Author: gordon Date: Tue Jan 28 18:53:14 2020 New Revision: 357215 URL: https://svnweb.freebsd.org/changeset/base/357215 Log: Fix imprecise ordering of SSP canary initialization Submitted by: Kyle Evans Approved by: so Security: FreeBSD-EN-20:01.ssp Modified: releng/11.3/lib/libc/secure/stack_protector.c releng/12.0/lib/libc/secure/stack_protector.c releng/12.1/lib/libc/secure/stack_protector.c Modified: releng/11.3/lib/libc/secure/stack_protector.c ============================================================================== --- releng/11.3/lib/libc/secure/stack_protector.c Tue Jan 28 18:42:06 2020 (r357214) +++ releng/11.3/lib/libc/secure/stack_protector.c Tue Jan 28 18:53:14 2020 (r357215) @@ -40,11 +40,29 @@ __FBSDID("$FreeBSD$"); #include <unistd.h> #include "libc_private.h" +/* + * We give __guard_setup a defined priority early on so that statically linked + * applications have a defined priority at which __stack_chk_guard will be + * getting initialized. This will not matter to most applications, because + * they're either not usually statically linked or they simply don't do things + * in constructors that would be adversely affected by their positioning with + * respect to this initialization. + * + * This conditional should be removed when GCC 4.2 is removed. + */ +#if __has_attribute(__constructor__) || __GNUC_PREREQ__(4, 3) +#define _GUARD_SETUP_CTOR_ATTR \ + __attribute__((__constructor__ (200), __used__)); +#else +#define _GUARD_SETUP_CTOR_ATTR \ + __attribute__((__constructor__, __used__)); +#endif + extern int __sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen); long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; -static void __guard_setup(void) __attribute__((__constructor__, __used__)); +static void __guard_setup(void) _GUARD_SETUP_CTOR_ATTR; static void __fail(const char *); void __stack_chk_fail(void); void __chk_fail(void); Modified: releng/12.0/lib/libc/secure/stack_protector.c ============================================================================== --- releng/12.0/lib/libc/secure/stack_protector.c Tue Jan 28 18:42:06 2020 (r357214) +++ releng/12.0/lib/libc/secure/stack_protector.c Tue Jan 28 18:53:14 2020 (r357215) @@ -40,11 +40,29 @@ __FBSDID("$FreeBSD$"); #include <unistd.h> #include "libc_private.h" +/* + * We give __guard_setup a defined priority early on so that statically linked + * applications have a defined priority at which __stack_chk_guard will be + * getting initialized. This will not matter to most applications, because + * they're either not usually statically linked or they simply don't do things + * in constructors that would be adversely affected by their positioning with + * respect to this initialization. + * + * This conditional should be removed when GCC 4.2 is removed. + */ +#if __has_attribute(__constructor__) || __GNUC_PREREQ__(4, 3) +#define _GUARD_SETUP_CTOR_ATTR \ + __attribute__((__constructor__ (200), __used__)); +#else +#define _GUARD_SETUP_CTOR_ATTR \ + __attribute__((__constructor__, __used__)); +#endif + extern int __sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen); long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; -static void __guard_setup(void) __attribute__((__constructor__, __used__)); +static void __guard_setup(void) _GUARD_SETUP_CTOR_ATTR; static void __fail(const char *); void __stack_chk_fail(void); void __chk_fail(void); Modified: releng/12.1/lib/libc/secure/stack_protector.c ============================================================================== --- releng/12.1/lib/libc/secure/stack_protector.c Tue Jan 28 18:42:06 2020 (r357214) +++ releng/12.1/lib/libc/secure/stack_protector.c Tue Jan 28 18:53:14 2020 (r357215) @@ -40,11 +40,29 @@ __FBSDID("$FreeBSD$"); #include <unistd.h> #include "libc_private.h" +/* + * We give __guard_setup a defined priority early on so that statically linked + * applications have a defined priority at which __stack_chk_guard will be + * getting initialized. This will not matter to most applications, because + * they're either not usually statically linked or they simply don't do things + * in constructors that would be adversely affected by their positioning with + * respect to this initialization. + * + * This conditional should be removed when GCC 4.2 is removed. + */ +#if __has_attribute(__constructor__) || __GNUC_PREREQ__(4, 3) +#define _GUARD_SETUP_CTOR_ATTR \ + __attribute__((__constructor__ (200), __used__)); +#else +#define _GUARD_SETUP_CTOR_ATTR \ + __attribute__((__constructor__, __used__)); +#endif + extern int __sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen); long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; -static void __guard_setup(void) __attribute__((__constructor__, __used__)); +static void __guard_setup(void) _GUARD_SETUP_CTOR_ATTR; static void __fail(const char *); void __stack_chk_fail(void); void __chk_fail(void);
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