linux-kernel - [PATCH 4.14 140/148] bpf: Explicitly memset some bpf info structures declared on the stack

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200401161605.620622049@linuxfoundation.org>
Date:   Wed,  1 Apr 2020 18:18:52 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Daniel Borkmann <daniel@...earbox.net>,
        Yonghong Song <yhs@...com>
Subject: [PATCH 4.14 140/148] bpf: Explicitly memset some bpf info structures declared on the stack

From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

commit 5c6f25887963f15492b604dd25cb149c501bbabf upstream.

Trying to initialize a structure with "= {};" will not always clean out
all padding locations in a structure. So be explicit and call memset to
initialize everything for a number of bpf information structures that
are then copied from userspace, sometimes from smaller memory locations
than the size of the structure.

Reported-by: Daniel Borkmann <daniel@...earbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
Acked-by: Yonghong Song <yhs@...com>
Link: https://lore.kernel.org/bpf/20200320162258.GA794295@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 kernel/bpf/syscall.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1364,7 +1364,7 @@ static int bpf_prog_get_info_by_fd(struc
 				   union bpf_attr __user *uattr)
 {
 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
-	struct bpf_prog_info info = {};
+	struct bpf_prog_info info;
 	u32 info_len = attr->info.info_len;
 	char __user *uinsns;
 	u32 ulen;
@@ -1375,6 +1375,7 @@ static int bpf_prog_get_info_by_fd(struc
 		return err;
 	info_len = min_t(u32, sizeof(info), info_len);
 
+	memset(&info, 0, sizeof(info));
 	if (copy_from_user(&info, uinfo, info_len))
 		return -EFAULT;
 
@@ -1420,7 +1421,7 @@ static int bpf_map_get_info_by_fd(struct
 				  union bpf_attr __user *uattr)
 {
 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
-	struct bpf_map_info info = {};
+	struct bpf_map_info info;
 	u32 info_len = attr->info.info_len;
 	int err;
 
@@ -1429,6 +1430,7 @@ static int bpf_map_get_info_by_fd(struct
 		return err;
 	info_len = min_t(u32, sizeof(info), info_len);
 
+	memset(&info, 0, sizeof(info));
 	info.type = map->map_type;
 	info.id = map->id;
 	info.key_size = map->key_size;