Commit 7263e22b authored by Tengda Wu's avatar Tengda Wu Committed by Pu Lehui
Browse files

Fix kabi breakage in struct bpf_link and bpf_link_ops 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9QG81


CVE: CVE-2024-35860

--------------------------------

After backport LTS commit 777a1adfea1c ("[Backport] bpf: support deferring
bpf_link dealloc to after RCU grace period"), `bpf_link` and `bpf_link_ops`
structures have changed, causing kabi breakage.

Use KABI_REPLACE and KABI_USE to fix kabi breakage in struct `bpf_link` and
struct `bpf_link_ops`.

Fixes: 1a1260f3db15 ("bpf: support deferring bpf_link dealloc to after RCU grace period")
Signed-off-by: default avatarTengda Wu <wutengda2@huawei.com>
Signed-off-by: default avatarPu Lehui <pulehui@huawei.com>
parent 12775e76

include/linux/bpf.h

+7 −8
Original line number Diff line number Diff line
@@ -1585,10 +1585,10 @@ struct bpf_link { 
	/* rcu is used before freeing, work can be used to schedule that

	 * RCU-based freeing before that, so they never overlap

	 */

	union {

	KABI_REPLACE(struct work_struct work, union {

		struct rcu_head rcu;

		struct work_struct work;

	};

	})



	KABI_RESERVE(1)

	KABI_RESERVE(2)
@@ -1602,11 +1602,6 @@ struct bpf_link_ops { 
	 * waiting

	 */

	void (*dealloc)(struct bpf_link *link);

	/* deallocate link resources callback, called after RCU grace period;

	 * if underlying BPF program is sleepable we go through tasks trace

	 * RCU GP and then "classic" RCU GP

	 */

	void (*dealloc_deferred)(struct bpf_link *link);

	int (*detach)(struct bpf_link *link);

	int (*update_prog)(struct bpf_link *link, struct bpf_prog *new_prog,

			   struct bpf_prog *old_prog);
@@ -1616,7 +1611,11 @@ struct bpf_link_ops { 
	int (*update_map)(struct bpf_link *link, struct bpf_map *new_map,

			  struct bpf_map *old_map);



	KABI_RESERVE(1)

	/* deallocate link resources callback, called after RCU grace period;

	 * if underlying BPF program is sleepable we go through tasks trace

	 * RCU GP and then "classic" RCU GP

	 */

	KABI_USE(1, void (*dealloc_deferred)(struct bpf_link *link))

	KABI_RESERVE(2)

	KABI_RESERVE(3)

	KABI_RESERVE(4)