| From 56292976673ff7e2e5ef4cba723bdac1ed78d6fe Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Date: Fri, 20 Mar 2020 17:22:58 +0100 |
| Subject: [PATCH] bpf: Explicitly memset some bpf info structures declared on |
| the stack |
| |
| 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: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c |
| index 577b7b3e7bfe..6d37931145d8 100644 |
| --- a/kernel/bpf/btf.c |
| +++ b/kernel/bpf/btf.c |
| @@ -3449,7 +3449,7 @@ 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; |
| @@ -3458,6 +3458,7 @@ 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 502274a7cea2..7af0e2f39065 100644 |
| --- a/kernel/bpf/syscall.c |
| +++ b/kernel/bpf/syscall.c |
| @@ -2275,7 +2275,7 @@ 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; |
| @@ -2287,6 +2287,7 @@ 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; |
| |
| @@ -2550,7 +2551,7 @@ 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; |
| |
| @@ -2559,6 +2560,7 @@ 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; |
| -- |
| 2.7.4 |
| |