[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.fat...@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