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authorAlexei Starovoitov <ast@kernel.org>2018-11-22 10:49:56 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2018-11-22 21:29:40 +0100
commit813961de3ee6474dd5703e883471fd941d6c8f69 (patch)
treec96784f1ab86f2fcdf98c420fd1f7fcb714e7107 /kernel
parentdde7011a824cfa815b03f853ec985ff46b740939 (diff)
bpf: fix integer overflow in queue_stack_map
Fix the following issues: - allow queue_stack_map for root only - fix u32 max_entries overflow - disallow value_size == 0 Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Reported-by: Wei Wu <ww9210@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Mauricio Vasquez B <mauricio.vasquez@polito.it> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/queue_stack_maps.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
index 8bbd72d3a121..b384ea9f3254 100644
--- a/kernel/bpf/queue_stack_maps.c
+++ b/kernel/bpf/queue_stack_maps.c
@@ -7,6 +7,7 @@
#include <linux/bpf.h>
#include <linux/list.h>
#include <linux/slab.h>
+#include <linux/capability.h>
#include "percpu_freelist.h"
#define QUEUE_STACK_CREATE_FLAG_MASK \
@@ -45,8 +46,12 @@ static bool queue_stack_map_is_full(struct bpf_queue_stack *qs)
/* Called from syscall */
static int queue_stack_map_alloc_check(union bpf_attr *attr)
{
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
/* check sanity of attributes */
if (attr->max_entries == 0 || attr->key_size != 0 ||
+ attr->value_size == 0 ||
attr->map_flags & ~QUEUE_STACK_CREATE_FLAG_MASK)
return -EINVAL;
@@ -63,15 +68,10 @@ static struct bpf_map *queue_stack_map_alloc(union bpf_attr *attr)
{
int ret, numa_node = bpf_map_attr_numa_node(attr);
struct bpf_queue_stack *qs;
- u32 size, value_size;
- u64 queue_size, cost;
-
- size = attr->max_entries + 1;
- value_size = attr->value_size;
-
- queue_size = sizeof(*qs) + (u64) value_size * size;
+ u64 size, queue_size, cost;
- cost = queue_size;
+ size = (u64) attr->max_entries + 1;
+ cost = queue_size = sizeof(*qs) + size * attr->value_size;
if (cost >= U32_MAX - PAGE_SIZE)
return ERR_PTR(-E2BIG);