From 5775eb40862b67468ced816e6d7560dbe22a3670 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 15 Jun 2020 12:15:29 -0400 Subject: [PATCH] calloc: Make sure we always have an overflow-checking calloc() available MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This tries to make sure that everywhere in this source tree, we always have an appropriate version of calloc() (i.e. grub_calloc(), xcalloc(), etc.) available, and that they all safely check for overflow and return NULL when it would occur. Signed-off-by: Peter Jones Reviewed-by: Daniel Kiper Signed-off-by: Stefan Sørensen --- grub-core/kern/emu/misc.c | 12 +++++++++ grub-core/kern/emu/mm.c | 10 ++++++++ grub-core/kern/mm.c | 40 ++++++++++++++++++++++++++++++ grub-core/lib/libgcrypt_wrap/mem.c | 11 ++++++-- grub-core/lib/posix_wrap/stdlib.h | 8 +++++- include/grub/emu/misc.h | 1 + include/grub/mm.h | 6 +++++ 7 files changed, 85 insertions(+), 3 deletions(-) diff --git a/grub-core/kern/emu/misc.c b/grub-core/kern/emu/misc.c index 65db79baa..dfd8a8ec4 100644 --- a/grub-core/kern/emu/misc.c +++ b/grub-core/kern/emu/misc.c @@ -85,6 +85,18 @@ grub_util_error (const char *fmt, ...) exit (1); } +void * +xcalloc (grub_size_t nmemb, grub_size_t size) +{ + void *p; + + p = calloc (nmemb, size); + if (!p) + grub_util_error ("%s", _("out of memory")); + + return p; +} + void * xmalloc (grub_size_t size) { diff --git a/grub-core/kern/emu/mm.c b/grub-core/kern/emu/mm.c index f262e95e3..145b01d37 100644 --- a/grub-core/kern/emu/mm.c +++ b/grub-core/kern/emu/mm.c @@ -25,6 +25,16 @@ #include #include +void * +grub_calloc (grub_size_t nmemb, grub_size_t size) +{ + void *ret; + ret = calloc (nmemb, size); + if (!ret) + grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); + return ret; +} + void * grub_malloc (grub_size_t size) { diff --git a/grub-core/kern/mm.c b/grub-core/kern/mm.c index ee88ff611..f2822a836 100644 --- a/grub-core/kern/mm.c +++ b/grub-core/kern/mm.c @@ -67,8 +67,10 @@ #include #include #include +#include #ifdef MM_DEBUG +# undef grub_calloc # undef grub_malloc # undef grub_zalloc # undef grub_realloc @@ -375,6 +377,30 @@ grub_memalign (grub_size_t align, grub_size_t size) return 0; } +/* + * Allocate NMEMB instances of SIZE bytes and return the pointer, or error on + * integer overflow. + */ +void * +grub_calloc (grub_size_t nmemb, grub_size_t size) +{ + void *ret; + grub_size_t sz = 0; + + if (grub_mul (nmemb, size, &sz)) + { + grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected")); + return NULL; + } + + ret = grub_memalign (0, sz); + if (!ret) + return NULL; + + grub_memset (ret, 0, sz); + return ret; +} + /* Allocate SIZE bytes and return the pointer. */ void * grub_malloc (grub_size_t size) @@ -561,6 +587,20 @@ grub_mm_dump (unsigned lineno) grub_printf ("\n"); } +void * +grub_debug_calloc (const char *file, int line, grub_size_t nmemb, grub_size_t size) +{ + void *ptr; + + if (grub_mm_debug) + grub_printf ("%s:%d: calloc (0x%" PRIxGRUB_SIZE ", 0x%" PRIxGRUB_SIZE ") = ", + file, line, size); + ptr = grub_calloc (nmemb, size); + if (grub_mm_debug) + grub_printf ("%p\n", ptr); + return ptr; +} + void * grub_debug_malloc (const char *file, int line, grub_size_t size) { diff --git a/grub-core/lib/libgcrypt_wrap/mem.c b/grub-core/lib/libgcrypt_wrap/mem.c index beeb661a3..74c6eafe5 100644 --- a/grub-core/lib/libgcrypt_wrap/mem.c +++ b/grub-core/lib/libgcrypt_wrap/mem.c @@ -4,6 +4,7 @@ #include #include #include +#include GRUB_MOD_LICENSE ("GPLv3+"); @@ -36,7 +37,10 @@ void * gcry_xcalloc (size_t n, size_t m) { void *ret; - ret = grub_zalloc (n * m); + size_t sz; + if (grub_mul (n, m, &sz)) + grub_fatal ("gcry_xcalloc would overflow"); + ret = grub_zalloc (sz); if (!ret) grub_fatal ("gcry_xcalloc failed"); return ret; @@ -56,7 +60,10 @@ void * gcry_xcalloc_secure (size_t n, size_t m) { void *ret; - ret = grub_zalloc (n * m); + size_t sz; + if (grub_mul (n, m, &sz)) + grub_fatal ("gcry_xcalloc would overflow"); + ret = grub_zalloc (sz); if (!ret) grub_fatal ("gcry_xcalloc failed"); return ret; diff --git a/grub-core/lib/posix_wrap/stdlib.h b/grub-core/lib/posix_wrap/stdlib.h index 3b46f47ff..7a8d385e9 100644 --- a/grub-core/lib/posix_wrap/stdlib.h +++ b/grub-core/lib/posix_wrap/stdlib.h @@ -21,6 +21,7 @@ #include #include +#include static inline void free (void *ptr) @@ -37,7 +38,12 @@ malloc (grub_size_t size) static inline void * calloc (grub_size_t size, grub_size_t nelem) { - return grub_zalloc (size * nelem); + grub_size_t sz; + + if (grub_mul (size, nelem, &sz)) + return NULL; + + return grub_zalloc (sz); } static inline void * diff --git a/include/grub/emu/misc.h b/include/grub/emu/misc.h index ce464cfd0..ff9c48a64 100644 --- a/include/grub/emu/misc.h +++ b/include/grub/emu/misc.h @@ -47,6 +47,7 @@ grub_util_device_is_mapped (const char *dev); #define GRUB_HOST_PRIuLONG_LONG "llu" #define GRUB_HOST_PRIxLONG_LONG "llx" +void * EXPORT_FUNC(xcalloc) (grub_size_t nmemb, grub_size_t size) WARN_UNUSED_RESULT; void * EXPORT_FUNC(xmalloc) (grub_size_t size) WARN_UNUSED_RESULT; void * EXPORT_FUNC(xrealloc) (void *ptr, grub_size_t size) WARN_UNUSED_RESULT; char * EXPORT_FUNC(xstrdup) (const char *str) WARN_UNUSED_RESULT; diff --git a/include/grub/mm.h b/include/grub/mm.h index 28e2e53eb..9c38dd3ca 100644 --- a/include/grub/mm.h +++ b/include/grub/mm.h @@ -29,6 +29,7 @@ #endif void grub_mm_init_region (void *addr, grub_size_t size); +void *EXPORT_FUNC(grub_calloc) (grub_size_t nmemb, grub_size_t size); void *EXPORT_FUNC(grub_malloc) (grub_size_t size); void *EXPORT_FUNC(grub_zalloc) (grub_size_t size); void EXPORT_FUNC(grub_free) (void *ptr); @@ -48,6 +49,9 @@ extern int EXPORT_VAR(grub_mm_debug); void grub_mm_dump_free (void); void grub_mm_dump (unsigned lineno); +#define grub_calloc(nmemb, size) \ + grub_debug_calloc (GRUB_FILE, __LINE__, nmemb, size) + #define grub_malloc(size) \ grub_debug_malloc (GRUB_FILE, __LINE__, size) @@ -63,6 +67,8 @@ void grub_mm_dump (unsigned lineno); #define grub_free(ptr) \ grub_debug_free (GRUB_FILE, __LINE__, ptr) +void *EXPORT_FUNC(grub_debug_calloc) (const char *file, int line, + grub_size_t nmemb, grub_size_t size); void *EXPORT_FUNC(grub_debug_malloc) (const char *file, int line, grub_size_t size); void *EXPORT_FUNC(grub_debug_zalloc) (const char *file, int line, -- 2.26.2