bpf: don't bother with getname/kern_path - use user_path_at

kernel/bpf/inode.c misuses kern_path...() - it's much simpler (and
more efficient, on top of that) to use user_path...() counterparts
rather than bothering with doing getname() manually.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200120232858.GF8904@ZenIV.linux.org.uk
This commit is contained in:
Al Viro 2020-01-20 23:28:58 +00:00 committed by Daniel Borkmann
parent d49d0661b9
commit b87121dd3f
1 changed files with 13 additions and 30 deletions

View File

@ -380,7 +380,7 @@ static const struct inode_operations bpf_dir_iops = {
.unlink = simple_unlink,
};
static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
static int bpf_obj_do_pin(const char __user *pathname, void *raw,
enum bpf_type type)
{
struct dentry *dentry;
@ -389,7 +389,7 @@ static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
umode_t mode;
int ret;
dentry = kern_path_create(AT_FDCWD, pathname->name, &path, 0);
dentry = user_path_create(AT_FDCWD, pathname, &path, 0);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@ -422,30 +422,22 @@ static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
int bpf_obj_pin_user(u32 ufd, const char __user *pathname)
{
struct filename *pname;
enum bpf_type type;
void *raw;
int ret;
pname = getname(pathname);
if (IS_ERR(pname))
return PTR_ERR(pname);
raw = bpf_fd_probe_obj(ufd, &type);
if (IS_ERR(raw)) {
ret = PTR_ERR(raw);
goto out;
}
if (IS_ERR(raw))
return PTR_ERR(raw);
ret = bpf_obj_do_pin(pname, raw, type);
ret = bpf_obj_do_pin(pathname, raw, type);
if (ret != 0)
bpf_any_put(raw, type);
out:
putname(pname);
return ret;
}
static void *bpf_obj_do_get(const struct filename *pathname,
static void *bpf_obj_do_get(const char __user *pathname,
enum bpf_type *type, int flags)
{
struct inode *inode;
@ -453,7 +445,7 @@ static void *bpf_obj_do_get(const struct filename *pathname,
void *raw;
int ret;
ret = kern_path(pathname->name, LOOKUP_FOLLOW, &path);
ret = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW, &path);
if (ret)
return ERR_PTR(ret);
@ -480,36 +472,27 @@ static void *bpf_obj_do_get(const struct filename *pathname,
int bpf_obj_get_user(const char __user *pathname, int flags)
{
enum bpf_type type = BPF_TYPE_UNSPEC;
struct filename *pname;
int ret = -ENOENT;
int f_flags;
void *raw;
int ret;
f_flags = bpf_get_file_flag(flags);
if (f_flags < 0)
return f_flags;
pname = getname(pathname);
if (IS_ERR(pname))
return PTR_ERR(pname);
raw = bpf_obj_do_get(pname, &type, f_flags);
if (IS_ERR(raw)) {
ret = PTR_ERR(raw);
goto out;
}
raw = bpf_obj_do_get(pathname, &type, f_flags);
if (IS_ERR(raw))
return PTR_ERR(raw);
if (type == BPF_TYPE_PROG)
ret = bpf_prog_new_fd(raw);
else if (type == BPF_TYPE_MAP)
ret = bpf_map_new_fd(raw, f_flags);
else
goto out;
return -ENOENT;
if (ret < 0)
bpf_any_put(raw, type);
out:
putname(pname);
return ret;
}