[PATCH 5.18 136/141] bpf: Use safer kvmalloc_array() where possible

Greg Kroah-Hartman
2022-06-20T13:07:16Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit fd58f7df2415ef747782e01f94880fefad1247cf upstream.

The kvmalloc_array() function is safer because it has a check for
integer overflows. These sizes come from the user and I was not
able to see any bounds checking so an integer overflow seems like a
realistic concern.

Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/Yo9VRVMeHbALyjUH@kili
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/bpf_trace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2433,7 +2433,7 @@ int bpf_kprobe_multi_link_attach(const u
return -EINVAL;

size = cnt * sizeof(*addrs);
- addrs = kvmalloc(size, GFP_KERNEL);
+ addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
if (!addrs)
return -ENOMEM;

@@ -2450,7 +2450,7 @@ int bpf_kprobe_multi_link_attach(const u

ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
if (ucookies) {
- cookies = kvmalloc(size, GFP_KERNEL);
+ cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
if (!cookies) {
err = -ENOMEM;
goto error;