| From 5c6f25887963f15492b604dd25cb149c501bbabf Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Date: Fri, 20 Mar 2020 17:22:58 +0100 |
| Subject: bpf: Explicitly memset some bpf info structures declared on the stack |
| |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.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@iogearbox.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> |
| Acked-by: Yonghong Song <yhs@fb.com> |
| Link: https://lore.kernel.org/bpf/20200320162258.GA794295@kroah.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| kernel/bpf/btf.c | 3 ++- |
| kernel/bpf/syscall.c | 6 ++++-- |
| 2 files changed, 6 insertions(+), 3 deletions(-) |
| |
| --- a/kernel/bpf/btf.c |
| +++ b/kernel/bpf/btf.c |
| @@ -4218,7 +4218,7 @@ int btf_get_info_by_fd(const struct 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; |
| @@ -4227,6 +4227,7 @@ int btf_get_info_by_fd(const struct 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; |
| |
| --- a/kernel/bpf/syscall.c |
| +++ b/kernel/bpf/syscall.c |
| @@ -2477,7 +2477,7 @@ 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; |
| struct bpf_prog_stats stats; |
| char __user *uinsns; |
| @@ -2489,6 +2489,7 @@ 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; |
| |
| @@ -2752,7 +2753,7 @@ 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; |
| |
| @@ -2761,6 +2762,7 @@ 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; |