From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 26 May 2022 13:24:05 +0300
Subject: bpf: Use safer kvmalloc_array() where possible
Patch-mainline: v5.19-rc2
Git-commit: fd58f7df2415ef747782e01f94880fefad1247cf
References: jsc#PED-1377

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>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
 kernel/trace/bpf_trace.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2268,11 +2268,11 @@ static int copy_user_syms(struct user_sy
 	int err = -ENOMEM;
 	unsigned int i;
 
-	syms = kvmalloc(cnt * sizeof(*syms), GFP_KERNEL);
+	syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
 	if (!syms)
 		goto error;
 
-	buf = kvmalloc(cnt * KSYM_NAME_LEN, GFP_KERNEL);
+	buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
 	if (!buf)
 		goto error;
 
@@ -2469,7 +2469,7 @@ 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;
 
@@ -2494,7 +2494,7 @@ 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;