From: Xu Kuohai <xukuohai@huawei.com>

Fix an off-by-one error in check_indirect_jump() that skips the last
element returned by copy_insn_array_uniq().

Fixes: 493d9e0d6083 ("bpf, x86: add support for indirect jumps")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
---
 kernel/bpf/verifier.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index faa1ecc1fe9d..22605d9e0ffa 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -20336,7 +20336,7 @@ static int check_indirect_jump(struct bpf_verifier_env *env, struct bpf_insn *in
 		return -EINVAL;
 	}
 
-	for (i = 0; i < n - 1; i++) {
+	for (i = 0; i < n; i++) {
 		other_branch = push_stack(env, env->gotox_tmp_buf->items[i],
 					  env->insn_idx, env->cur_state->speculative);
 		if (IS_ERR(other_branch))
-- 
2.47.3

On 26/01/14 05:39PM, Xu Kuohai wrote:
> From: Xu Kuohai <xukuohai@huawei.com>
> 
> Fix an off-by-one error in check_indirect_jump() that skips the last
> element returned by copy_insn_array_uniq().
> 
> Fixes: 493d9e0d6083 ("bpf, x86: add support for indirect jumps")
> Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
> ---
>  kernel/bpf/verifier.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index faa1ecc1fe9d..22605d9e0ffa 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -20336,7 +20336,7 @@ static int check_indirect_jump(struct bpf_verifier_env *env, struct bpf_insn *in
>  		return -EINVAL;
>  	}
>  
> -	for (i = 0; i < n - 1; i++) {
> +	for (i = 0; i < n; i++) {
>  		other_branch = push_stack(env, env->gotox_tmp_buf->items[i],
>  					  env->insn_idx, env->cur_state->speculative);
>  		if (IS_ERR(other_branch))
> -- 
> 2.47.3

Nack, the last state doesn't require a push_stack() call, it is
verified directly under this loop. Instead of this patch, just
add another call to mark_indirect_target().

On 1/14/2026 6:29 PM, Anton Protopopov wrote:
> On 26/01/14 05:39PM, Xu Kuohai wrote:
>> From: Xu Kuohai <xukuohai@huawei.com>
>>
>> Fix an off-by-one error in check_indirect_jump() that skips the last
>> element returned by copy_insn_array_uniq().
>>
>> Fixes: 493d9e0d6083 ("bpf, x86: add support for indirect jumps")
>> Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
>> ---
>>   kernel/bpf/verifier.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
>> index faa1ecc1fe9d..22605d9e0ffa 100644
>> --- a/kernel/bpf/verifier.c
>> +++ b/kernel/bpf/verifier.c
>> @@ -20336,7 +20336,7 @@ static int check_indirect_jump(struct bpf_verifier_env *env, struct bpf_insn *in
>>   		return -EINVAL;
>>   	}
>>   
>> -	for (i = 0; i < n - 1; i++) {
>> +	for (i = 0; i < n; i++) {
>>   		other_branch = push_stack(env, env->gotox_tmp_buf->items[i],
>>   					  env->insn_idx, env->cur_state->speculative);
>>   		if (IS_ERR(other_branch))
>> -- 
>> 2.47.3
> 
> Nack, the last state doesn't require a push_stack() call, it is
> verified directly under this loop. Instead of this patch, just
> add another call to mark_indirect_target().

Ok, I see. Thanks for the explanation.