Commit d5fb316e authored by Andrii Nakryiko's avatar Andrii Nakryiko
Browse files

Merge branch 'add-the-missing-bpf_link_type-invocation-for-sockmap' 

Hou Tao says:

====================
Add the missing BPF_LINK_TYPE invocation for sockmap

From: Hou Tao <houtao1@huawei.com>

Hi,

The tiny patch set fixes the out-of-bound read problem when reading the
fdinfo of sock map link fd. And in order to spot such omission early for
the newly-added link type in the future, it also checks the validity of
the link->type and adds a WARN_ONCE() for missed invocation.

Please see individual patches for more details. And comments are always
welcome.

v3:
  * patch #2: check and warn the validity of link->type instead of
    adding a static assertion for bpf_link_type_strs array.

v2: http://lore.kernel.org/bpf/d49fa2f4-f743-c763-7579-c3cab4dd88cb@huaweicloud.com
====================

Link: https://lore.kernel.org/r/20241024013558.1135167-1-houtao@huaweicloud.com


Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
parents 9806f283 8421d4c8

include/linux/bpf_types.h

+1 −0
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ BPF_LINK_TYPE(BPF_LINK_TYPE_XDP, xdp) 
BPF_LINK_TYPE(BPF_LINK_TYPE_NETFILTER, netfilter)

BPF_LINK_TYPE(BPF_LINK_TYPE_TCX, tcx)

BPF_LINK_TYPE(BPF_LINK_TYPE_NETKIT, netkit)

BPF_LINK_TYPE(BPF_LINK_TYPE_SOCKMAP, sockmap)

#endif

#ifdef CONFIG_PERF_EVENTS

BPF_LINK_TYPE(BPF_LINK_TYPE_PERF_EVENT, perf)

include/uapi/linux/bpf.h

+3 −0
Original line number Diff line number Diff line
@@ -1121,6 +1121,9 @@ enum bpf_attach_type { 


#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE



/* Add BPF_LINK_TYPE(type, name) in bpf_types.h to keep bpf_link_type_strs[]

 * in sync with the definitions below.

 */

enum bpf_link_type {

	BPF_LINK_TYPE_UNSPEC = 0,

	BPF_LINK_TYPE_RAW_TRACEPOINT = 1,

kernel/bpf/syscall.c

+9 −5
Original line number Diff line number Diff line
@@ -3069,13 +3069,17 @@ static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 
{

	const struct bpf_link *link = filp->private_data;

	const struct bpf_prog *prog = link->prog;

	enum bpf_link_type type = link->type;

	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };



	seq_printf(m,

		   "link_type:\t%s\n"

		   "link_id:\t%u\n",

		   bpf_link_type_strs[link->type],

		   link->id);

	if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {

		seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);

	} else {

		WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);

		seq_printf(m, "link_type:\t<%u>\n", type);

	}

	seq_printf(m, "link_id:\t%u\n", link->id);



	if (prog) {

		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));

		seq_printf(m,

tools/include/uapi/linux/bpf.h

+3 −0
Original line number Diff line number Diff line
@@ -1121,6 +1121,9 @@ enum bpf_attach_type { 


#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE



/* Add BPF_LINK_TYPE(type, name) in bpf_types.h to keep bpf_link_type_strs[]

 * in sync with the definitions below.

 */

enum bpf_link_type {

	BPF_LINK_TYPE_UNSPEC = 0,

	BPF_LINK_TYPE_RAW_TRACEPOINT = 1,