Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit cb57b8b8 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman Committed by Greg Kroah-Hartman
Browse files

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



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: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200320162258.GA794295@kroah.com


(cherry picked from commit 269efb7fc478563a7e7b22590d8076823f4ac82a)
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
Change-Id: I52a2cab20aa310085ec104bd811ac4f2b83657b6
parent de2b205f

kernel/bpf/btf.c

+2 −1
Original line number Diff line number Diff line
@@ -2387,7 +2387,7 @@ 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;
@@ -2396,6 +2396,7 @@ 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;

kernel/bpf/syscall.c

+4 −2
Original line number Diff line number Diff line
@@ -1958,7 +1958,7 @@ 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;

	char __user *uinsns;

	u32 ulen;
@@ -1969,6 +1969,7 @@ 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;
@@ -2136,7 +2137,7 @@ 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;
@@ -2145,6 +2146,7 @@ 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;