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bpf: Explicitly memset some bpf info structures declared on the stack

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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
This commit is contained in:
Greg Kroah-Hartman 2020-03-20 17:22:58 +01:00 committed by Daniel Borkmann
parent 8096f22942
commit 5c6f258879
2 changed files with 6 additions and 3 deletions
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3
kernel/bpf/btf.c
View File

@ -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;

6
kernel/bpf/syscall.c
View File

@ -2795,7 +2795,7 @@ 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;
@ -2807,6 +2807,7 @@ 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;
@ -3070,7 +3071,7 @@ 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;
@ -3079,6 +3080,7 @@ 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;