From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: "Alexei Starovoitov" <ast@kernel.org>,
"Martin KaFai Lau" <kafai@fb.com>,
"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
"Andrii Nakryiko" <andriin@fb.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Maciej Żenczykowski" <maze@google.com>,
"John Stultz" <john.stultz@linaro.org>,
"Alexander Potapenko" <glider@google.com>,
"Alistair Delva" <adelva@google.com>
Subject: [PATCH] bpf: explicitly memset some bpf info structures declared on the stack
Date: Fri, 20 Mar 2020 17:22:58 +0100 [thread overview]
Message-ID: <20200320162258.GA794295@kroah.com> (raw)
In-Reply-To: <20200320161515.GA778529@kroah.com>
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@iogearbox.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Note, this is separate from my previous patch, both are needed.
kernel/bpf/btf.c | 3 ++-
kernel/bpf/syscall.c | 6 ++++--
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 787140095e58..2fc945fcf952 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4564,7 +4564,7 @@ int btf_get_info_by_fd(const struct btf *btf,
union bpf_attr __user *uattr)
{
struct bpf_btf_info __user *uinfo;
- struct bpf_btf_info info = {};
+ struct bpf_btf_info info;
u32 info_copy, btf_copy;
void __user *ubtf;
u32 uinfo_len;
@@ -4573,6 +4573,7 @@ int btf_get_info_by_fd(const struct btf *btf,
uinfo_len = attr->info.info_len;
info_copy = min_t(u32, uinfo_len, sizeof(info));
+ memset(&info, 0, sizeof(info));
if (copy_from_user(&info, uinfo, info_copy))
return -EFAULT;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index a4b1de8ea409..84213cc5d016 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2787,7 +2787,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
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;
struct bpf_prog_stats stats;
char __user *uinsns;
@@ -2799,6 +2799,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
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;
@@ -3062,7 +3063,7 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map,
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;
@@ -3071,6 +3072,7 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map,
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;
--
2.25.2
next prev parent reply other threads:[~2020-03-20 16:23 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-20 9:48 [PATCH] bpf: explicitly memset the bpf_attr structure Greg Kroah-Hartman
2020-03-20 15:23 ` Yonghong Song
2020-03-20 15:46 ` Greg Kroah-Hartman
2020-03-20 15:24 ` Daniel Borkmann
2020-03-20 15:31 ` Yonghong Song
2020-03-20 15:45 ` Greg Kroah-Hartman
2020-03-20 16:04 ` Daniel Borkmann
2020-03-20 16:15 ` Greg Kroah-Hartman
2020-03-20 16:22 ` Greg Kroah-Hartman [this message]
2020-03-20 18:34 ` [PATCH] bpf: explicitly memset some bpf info structures declared on the stack Yonghong Song
2020-03-20 20:07 ` Daniel Borkmann
2020-03-20 20:07 ` [PATCH] bpf: explicitly memset the bpf_attr structure Daniel Borkmann
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