[PATCH 3/6] dlmalloc: fail allocations exceeding MALLOC_MAX_SIZE

[Ahmad Fatoum]

We already enforce a maximum allocation size of LONG_MAX in dlmalloc,
but this is larger than any reasonable allocation size we would have.

Let's reduce it to the new common maximum of SZ_1G.

While at it, enforce this limit for all size and alignment
parameters.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 common/dlmalloc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/common/dlmalloc.c b/common/dlmalloc.c
index 731c46b584b0..2b5723e127c4 100644
--- a/common/dlmalloc.c
+++ b/common/dlmalloc.c
@@ -1162,7 +1162,7 @@ void *dlmalloc(size_t bytes)
 
 	INTERNAL_SIZE_T nb;
 
-	if ((long) bytes < 0) {
+	if (bytes > MALLOC_MAX_SIZE) {
 		errno = ENOMEM;
 		return NULL;
 	}
@@ -1499,7 +1499,7 @@ void *dlrealloc(void *oldmem, size_t bytes)
 	}
 #endif
 
-	if ((long)bytes < 0) {
+	if (bytes > MALLOC_MAX_SIZE) {
 		errno = ENOMEM;
 		return NULL;
 	}
@@ -1668,7 +1668,7 @@ void *dlmemalign(size_t alignment, size_t bytes)
 	mchunkptr remainder;	/* spare room at end to split off */
 	long remainder_size;	/* its size */
 
-	if ((long) bytes < 0) {
+	if (bytes > MALLOC_MAX_SIZE || alignment > MALLOC_MAX_SIZE) {
 		errno = ENOMEM;
 		return NULL;
 	}
@@ -1753,7 +1753,7 @@ void *dlcalloc(size_t n, size_t elem_size)
 	mchunkptr oldtop = top;
 	INTERNAL_SIZE_T oldtopsize = chunksize(top);
 
-	if ((long)n < 0) {
+	if (sz > MALLOC_MAX_SIZE) {
 		errno = ENOMEM;
 		return NULL;
 	}
-- 
2.39.5