Unverified Commit c47d45df authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
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!1337 [sync] PR-1335: bpf: Fix incorrect verifier pruning due to missing register precision taints 

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/1335 
 
PR sync from: Pu Lehui <pulehui@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/U3JJGUSJTF5PH22SUDWUTPBSGUN6AUFJ/ 
 
 
Link:https://gitee.com/openeuler/kernel/pulls/1337

 

Reviewed-by: default avatarXu Kuohai <xukuohai@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents 10c9fe8d a1b310b4

kernel/bpf/verifier.c

+15 −0
Original line number Diff line number Diff line
@@ -1922,6 +1922,21 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, 
			}

		} else if (opcode == BPF_EXIT) {

			return -ENOTSUPP;

		} else if (BPF_SRC(insn->code) == BPF_X) {

			if (!(*reg_mask & (dreg | sreg)))

				return 0;

			/* dreg <cond> sreg

			 * Both dreg and sreg need precision before

			 * this insn. If only sreg was marked precise

			 * before it would be equally necessary to

			 * propagate it to dreg.

			 */

			*reg_mask |= (sreg | dreg);

			 /* else dreg <cond> K

			  * Only dreg still needs precision before

			  * this insn, so for the K-based conditional

			  * there is nothing new to be marked.

			  */

		}

	} else if (class == BPF_LD) {

		if (!(*reg_mask & dreg))