[dpdk-stable] patch 'mem: fix overflow on allocation' has been queued to stable release 19.11.3

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/21/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Luca Boccassi

---
>From fd554a1f8f2a11739712f6367c0804e0943924a7 Mon Sep 17 00:00:00 2001
From: Bing Zhao <bingz at mellanox.com>
Date: Thu, 7 May 2020 16:02:54 +0800
Subject: [PATCH] mem: fix overflow on allocation

[ upstream commit b341a09c1dd3664b43d5b3a91b6a83136f2d4a12 ]

The size checking is done in the caller. The size parameter is an
unsigned (64b wide) right now, so the comparison with zero should be
enough in most cases. But it won't help in the following case.
If the allocating request input a huge number by mistake, e.g., some
overflow after the calculation (especially subtraction), the checking
in the caller will succeed since it is not zero. Indeed, there is not
enough space in the system to support such huge memory allocation.
Usually it will return failure in the following code. But if the
input size is just a little smaller than the UINT64_MAX, like -2 in
signed type.
The roundup will cause an overflow and then "reset" the size to 0,
and then only a header (128B now) with zero length will be returned.
The following will be the previous allocation header.
It should be OK in most cases if the application won't access the
memory body. Or else, some critical issue will be caused and not easy
to debug. So this issue should be prevented at the beginning, like
other big size failure, NULL pointer should be returned also.

Fixes: fdf20fa7bee9 ("add prefix to cache line macros")

Signed-off-by: Bing Zhao <bingz at mellanox.com>
Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 app/test/test_malloc.c              | 12 ++++++++++++
 lib/librte_eal/common/malloc_heap.c |  3 +++
 2 files changed, 15 insertions(+)

diff --git a/app/test/test_malloc.c b/app/test/test_malloc.c
index a16e28cc32..57f796f9e5 100644
--- a/app/test/test_malloc.c
+++ b/app/test/test_malloc.c
@@ -746,6 +746,18 @@ test_malloc_bad_params(void)
 	if (bad_ptr != NULL)
 		goto err_return;
 
+	/* rte_malloc expected to return null with size will cause overflow */
+	align = RTE_CACHE_LINE_SIZE;
+	size = (size_t)-8;
+
+	bad_ptr = rte_malloc(type, size, align);
+	if (bad_ptr != NULL)
+		goto err_return;
+
+	bad_ptr = rte_realloc(NULL, size, align);
+	if (bad_ptr != NULL)
+		goto err_return;
+
 	return 0;
 
 err_return:
diff --git a/lib/librte_eal/common/malloc_heap.c b/lib/librte_eal/common/malloc_heap.c
index 842eb9de75..bd5065698d 100644
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -241,6 +241,9 @@ heap_alloc(struct malloc_heap *heap, const char *type __rte_unused, size_t size,
 	size = RTE_CACHE_LINE_ROUNDUP(size);
 	align = RTE_CACHE_LINE_ROUNDUP(align);
 
+	/* roundup might cause an overflow */
+	if (size == 0)
+		return NULL;
 	elem = find_suitable_element(heap, size, flags, align, bound, contig);
 	if (elem != NULL) {
 		elem = malloc_elem_alloc(elem, size, align, bound, contig);
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-05-19 14:04:51.314294269 +0100
+++ 0167-mem-fix-overflow-on-allocation.patch	2020-05-19 14:04:44.512653738 +0100
@@ -1,8 +1,10 @@
-From b341a09c1dd3664b43d5b3a91b6a83136f2d4a12 Mon Sep 17 00:00:00 2001
+From fd554a1f8f2a11739712f6367c0804e0943924a7 Mon Sep 17 00:00:00 2001
 From: Bing Zhao <bingz at mellanox.com>
 Date: Thu, 7 May 2020 16:02:54 +0800
 Subject: [PATCH] mem: fix overflow on allocation
 
+[ upstream commit b341a09c1dd3664b43d5b3a91b6a83136f2d4a12 ]
+
 The size checking is done in the caller. The size parameter is an
 unsigned (64b wide) right now, so the comparison with zero should be
 enough in most cases. But it won't help in the following case.
@@ -22,7 +24,6 @@
 other big size failure, NULL pointer should be returned also.
 
 Fixes: fdf20fa7bee9 ("add prefix to cache line macros")
-Cc: stable at dpdk.org
 
 Signed-off-by: Bing Zhao <bingz at mellanox.com>
 Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
@@ -32,10 +33,10 @@
  2 files changed, 15 insertions(+)
 
 diff --git a/app/test/test_malloc.c b/app/test/test_malloc.c
-index 40a2f500cd..71b3cfdde5 100644
+index a16e28cc32..57f796f9e5 100644
 --- a/app/test/test_malloc.c
 +++ b/app/test/test_malloc.c
-@@ -846,6 +846,18 @@ test_malloc_bad_params(void)
+@@ -746,6 +746,18 @@ test_malloc_bad_params(void)
  	if (bad_ptr != NULL)
  		goto err_return;