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libxdp: Use IS_ERR_OR_NULL() for NULL checks on passed-in pointers
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Most of the libxdp APIs check if the argument passed in as the main object
is NULL before dereferencing it. However, the NULL checks should really use
IS_ERR_OR_NULL() as the APIs construction those objects can return error
pointers. Otherwise we'll still crash if a user accidentally passes in such
an error pointer.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
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@tohojo
tohojo committed Feb 3, 2023
1 parent 05071e5 commit 76bc988
Showing 1 changed file with 40 additions and 37 deletions.
77 changes: 40 additions & 37 deletions lib/libxdp/libxdp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -528,7 +528,7 @@ xdp_program__is_attached(const struct xdp_program *xdp_prog, int ifindex)
int xdp_program__set_chain_call_enabled(struct xdp_program *prog,
unsigned int action, bool enabled)
{
if (!prog || prog->prog_fd >= 0 || action >= XDP_DISPATCHER_RETVAL)
if (IS_ERR_OR_NULL(prog) || prog->prog_fd >= 0 || action >= XDP_DISPATCHER_RETVAL)
return -EINVAL;

if (enabled)
Expand All @@ -542,23 +542,23 @@ int xdp_program__set_chain_call_enabled(struct xdp_program *prog,
bool xdp_program__chain_call_enabled(const struct xdp_program *prog,
enum xdp_action action)
{
if (!prog || action >= XDP_DISPATCHER_RETVAL)
if (IS_ERR_OR_NULL(prog) || action >= XDP_DISPATCHER_RETVAL)
return false;

return !!(prog->chain_call_actions & (1U << action));
}

unsigned int xdp_program__run_prio(const struct xdp_program *prog)
{
if (!prog)
if (IS_ERR_OR_NULL(prog))
return XDP_DEFAULT_RUN_PRIO;

return prog->run_prio;
}

int xdp_program__set_run_prio(struct xdp_program *prog, unsigned int run_prio)
{
if (!prog || prog->prog_fd >= 0)
if (IS_ERR_OR_NULL(prog) || prog->prog_fd >= 0)
return -EINVAL;

prog->run_prio = run_prio;
Expand All @@ -567,42 +567,42 @@ int xdp_program__set_run_prio(struct xdp_program *prog, unsigned int run_prio)

const char *xdp_program__name(const struct xdp_program *prog)
{
if (!prog)
if (IS_ERR_OR_NULL(prog))
return NULL;

return prog->prog_name;
}

struct bpf_object *xdp_program__bpf_obj(struct xdp_program *prog)
{
if (!prog)
if (IS_ERR_OR_NULL(prog))
return NULL;

return prog->bpf_obj;
}

const unsigned char *xdp_program__tag(const struct xdp_program *prog)
{
if (!prog)
if (IS_ERR_OR_NULL(prog))
return NULL;

return prog->prog_tag;
}

uint32_t xdp_program__id(const struct xdp_program *xdp_prog)
uint32_t xdp_program__id(const struct xdp_program *prog)
{
if (!xdp_prog)
if (IS_ERR_OR_NULL(prog))
return 0;

return xdp_prog->prog_id;
return prog->prog_id;
}

int xdp_program__fd(const struct xdp_program *xdp_prog)
int xdp_program__fd(const struct xdp_program *prog)
{
if (!xdp_prog)
if (IS_ERR_OR_NULL(prog))
return -1;

return xdp_prog->prog_fd;
return prog->prog_fd;
}

int xdp_program__print_chain_call_actions(const struct xdp_program *prog,
Expand All @@ -612,7 +612,7 @@ int xdp_program__print_chain_call_actions(const struct xdp_program *prog,
char *pos = buf;
int i, len = 0;

if (!prog || !buf || !buf_len)
if (IS_ERR_OR_NULL(prog) || !buf || !buf_len)
return -EINVAL;

for (i = 0; i <= XDP_REDIRECT; i++) {
Expand Down Expand Up @@ -1292,7 +1292,7 @@ static int cmp_xdp_programs(const void *_a, const void *_b)

int xdp_program__pin(struct xdp_program *prog, const char *pin_path)
{
if (!prog || prog->prog_fd < 0)
if (IS_ERR_OR_NULL(prog) || prog->prog_fd < 0)
return -EINVAL;

return bpf_program__pin(prog->bpf_prog, pin_path);
Expand All @@ -1302,7 +1302,7 @@ static int xdp_program__load(struct xdp_program *prog)
{
int err, prog_fd;

if (!prog)
if (IS_ERR_OR_NULL(prog))
return -EINVAL;

if (prog->prog_fd >= 0)
Expand All @@ -1328,7 +1328,7 @@ static int xdp_program__load(struct xdp_program *prog)

struct xdp_program *xdp_program__clone(struct xdp_program *prog)
{
if (!prog || prog->prog_fd < 0)
if (IS_ERR_OR_NULL(prog) || prog->prog_fd < 0)
return ERR_PTR(-EINVAL);

/* Clone a loaded program struct by creating a new object from the
Expand Down Expand Up @@ -1360,7 +1360,7 @@ static int xdp_program__attach_single(struct xdp_program *prog, int ifindex,

static int xdp_multiprog__main_fd(struct xdp_multiprog *mp)
{
if (!mp)
if (IS_ERR_OR_NULL(mp))
return -EINVAL;

if (!mp->main_prog)
Expand All @@ -1371,15 +1371,15 @@ static int xdp_multiprog__main_fd(struct xdp_multiprog *mp)

static __u32 xdp_multiprog__main_id(struct xdp_multiprog *mp)
{
if (!mp || !mp->main_prog)
if (IS_ERR_OR_NULL(mp) || !mp->main_prog)
return 0;

return mp->main_prog->prog_id;
}

static int xdp_multiprog__hw_fd(struct xdp_multiprog *mp)
{
if (!mp)
if (IS_ERR_OR_NULL(mp))
return -EINVAL;

if (!mp->hw_prog)
Expand All @@ -1390,7 +1390,7 @@ static int xdp_multiprog__hw_fd(struct xdp_multiprog *mp)

static __u32 xdp_multiprog__hw_id(struct xdp_multiprog *mp)
{
if (!mp || !mp->hw_prog)
if (IS_ERR_OR_NULL(mp) || !mp->hw_prog)
return 0;

return mp->hw_prog->prog_id;
Expand Down Expand Up @@ -1513,7 +1513,7 @@ int xdp_program__attach(struct xdp_program *prog, int ifindex,
enum xdp_attach_mode mode,
unsigned int flags)
{
if (!prog || IS_ERR(prog))
if (IS_ERR_OR_NULL(prog))
return -EINVAL;

return xdp_program__attach_multi(&prog, 1, ifindex, mode, flags);
Expand Down Expand Up @@ -1653,7 +1653,7 @@ int xdp_program__detach(struct xdp_program *prog, int ifindex,
enum xdp_attach_mode mode,
unsigned int flags)
{
if (!prog || IS_ERR(prog))
if (IS_ERR_OR_NULL(prog) || IS_ERR(prog))
return -EINVAL;

return xdp_program__detach_multi(&prog, 1, ifindex, mode, flags);
Expand Down Expand Up @@ -1694,7 +1694,7 @@ static int xdp_multiprog__load(struct xdp_multiprog *mp)
char buf[100];
int err = 0;

if (!mp || !mp->main_prog || mp->is_loaded || xdp_multiprog__is_legacy(mp))
if (IS_ERR_OR_NULL(mp) || !mp->main_prog || mp->is_loaded || xdp_multiprog__is_legacy(mp))
return -EINVAL;

pr_debug("Loading multiprog dispatcher for %d programs\n",
Expand Down Expand Up @@ -1764,7 +1764,7 @@ static int xdp_multiprog__link_pinned_progs(struct xdp_multiprog *mp)
int err, lock_fd, i;
struct stat sb = {};

if (!mp || mp->first_prog)
if (IS_ERR_OR_NULL(mp) || mp->first_prog)
return -EINVAL;

bpffs_dir = get_bpffs_dir();
Expand Down Expand Up @@ -1850,7 +1850,7 @@ static int xdp_multiprog__fill_from_fd(struct xdp_multiprog *mp,
int map_fd = -1;
int err = 0;

if (!mp)
if (IS_ERR_OR_NULL(mp))
return -EINVAL;

if (prog_fd > 0) {
Expand Down Expand Up @@ -2249,7 +2249,7 @@ static int xdp_multiprog__link_prog(struct xdp_multiprog *mp,
char *attach_func;
__s32 btf_id;

if (!mp || !prog || !mp->is_loaded ||
if (IS_ERR_OR_NULL(mp) || IS_ERR_OR_NULL(prog) || !mp->is_loaded ||
mp->num_links >= mp->config.num_progs_enabled)
return -EINVAL;

Expand Down Expand Up @@ -2551,7 +2551,7 @@ static int xdp_multiprog__pin(struct xdp_multiprog *mp)
const char *bpffs_dir;
int err = 0, lock_fd;

if (!mp || xdp_multiprog__is_legacy(mp))
if (IS_ERR_OR_NULL(mp) || xdp_multiprog__is_legacy(mp))
return -EINVAL;

bpffs_dir = get_bpffs_dir();
Expand Down Expand Up @@ -2635,7 +2635,7 @@ static int xdp_multiprog__unpin(struct xdp_multiprog *mp)
const char *bpffs_dir;
int err = 0, lock_fd;

if (!mp || xdp_multiprog__is_legacy(mp))
if (IS_ERR_OR_NULL(mp) || xdp_multiprog__is_legacy(mp))
return -EINVAL;

bpffs_dir = get_bpffs_dir();
Expand Down Expand Up @@ -2702,7 +2702,7 @@ static int xdp_multiprog__attach(struct xdp_multiprog *old_mp,
{
int err = 0, prog_fd = -1, old_fd = -1, ifindex = -1;

if (!mp && !old_mp)
if (IS_ERR_OR_NULL(mp) && !old_mp)
return -EINVAL;

if (mode == XDP_MODE_HW)
Expand Down Expand Up @@ -2748,7 +2748,7 @@ int xdp_multiprog__detach(struct xdp_multiprog *mp)
{
int err = 0;

if (!mp || !mp->is_loaded)
if (IS_ERR_OR_NULL(mp) || !mp->is_loaded)
return -EINVAL;

if (mp->hw_prog) {
Expand All @@ -2771,7 +2771,7 @@ int xdp_multiprog__detach(struct xdp_multiprog *mp)
struct xdp_program *xdp_multiprog__next_prog(const struct xdp_program *prog,
const struct xdp_multiprog *mp)
{
if (!mp || xdp_multiprog__is_legacy(mp))
if (IS_ERR_OR_NULL(mp) || xdp_multiprog__is_legacy(mp))
return NULL;

if (prog)
Expand All @@ -2782,36 +2782,39 @@ struct xdp_program *xdp_multiprog__next_prog(const struct xdp_program *prog,

struct xdp_program *xdp_multiprog__hw_prog(const struct xdp_multiprog *mp)
{
if (!mp)
if (IS_ERR_OR_NULL(mp))
return NULL;

return mp->hw_prog;
}

enum xdp_attach_mode xdp_multiprog__attach_mode(const struct xdp_multiprog *mp)
{
if (!mp)
if (IS_ERR_OR_NULL(mp))
return XDP_MODE_UNSPEC;

return mp->attach_mode;
}

struct xdp_program *xdp_multiprog__main_prog(const struct xdp_multiprog *mp)
{
if (!mp)
if (IS_ERR_OR_NULL(mp))
return NULL;

return mp->main_prog;
}

bool xdp_multiprog__is_legacy(const struct xdp_multiprog *mp)
{
return !!(mp && mp->is_legacy);
if (IS_ERR_OR_NULL(mp))
return false;

return mp->is_legacy;
}

int xdp_multiprog__program_count(const struct xdp_multiprog *mp)
{
if (!mp)
if (IS_ERR_OR_NULL(mp))
return -EINVAL;

return mp->num_links;
Expand Down

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