[PATCH iproute2] lnstat:fix buffer overflow in lnstat lnstat segfaults when called the following command: $ lnstat -w 1

[PATCH iproute2] lnstat:fix buffer overflow in lnstat lnstat segfaults when called the following command: $ lnstat -w 1

[jiangheng (H)]

From d797c268003919f6e83c1bbdccebf62805dc2581 Mon Sep 17 00:00:00 2001
From: jiangheng <jiangheng12@huawei.com>
Date: Thu, 11 Nov 2021 18:20:26 +0800
Subject: [PATCH iproute2] lnstat:fix buffer overflow in lnstat lnstat
segfaults when called the following command: $ lnstat -w 1

[root@pm-104 conf.d]# lnstat -w 1
Segmentation fault (core dumped)

The maximum  value of th.num_lines is HDR_LINES(10),  h should not be equal to th.num_lines, array th.hdr may be out of bounds.

Signed-off-by jiangheng <jiangheng12@huawei.com>
---
misc/lnstat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/misc/lnstat.c b/misc/lnstat.c
index 89cb0e7e..26be852d 100644
--- a/misc/lnstat.c
+++ b/misc/lnstat.c
@@ -211,7 +211,7 @@ static struct table_hdr *build_hdr_string(struct lnstat_file *lnstat_files,
 		ofs += width+1;
 	}
 	/* fill in spaces */
-	for (h = 1; h <= th.num_lines; h++) {
+	for (h = 1; h < th.num_lines; h++) {
 		for (i = 0; i < ofs; i++) {
 			if (th.hdr[h][i] == '\0')
 				th.hdr[h][i] = ' ';
--
2.27.0

Re: [PATCH iproute2] lnstat:fix buffer overflow in lnstat lnstat segfaults when called the following command: $ lnstat -w 1

[Denis Kirjanov]

11/15/21 2:27 PM, jiangheng (H) пишет:
>  From d797c268003919f6e83c1bbdccebf62805dc2581 Mon Sep 17 00:00:00 2001
> From: jiangheng <jiangheng12@huawei.com>
> Date: Thu, 11 Nov 2021 18:20:26 +0800
> Subject: [PATCH iproute2] lnstat:fix buffer overflow in lnstat lnstat
Please adjust the subject line (lnstat is typed twice)

> segfaults when called the following command: $ lnstat -w 1
> 
> [root@pm-104 conf.d]# lnstat -w 1
> Segmentation fault (core dumped)
> 
> The maximum  value of th.num_lines is HDR_LINES(10),  h should not be equal to th.num_lines, array th.hdr may be out of bounds.
> 
> Signed-off-by jiangheng <jiangheng12@huawei.com>
> ---
> misc/lnstat.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/misc/lnstat.c b/misc/lnstat.c
> index 89cb0e7e..26be852d 100644
> --- a/misc/lnstat.c
> +++ b/misc/lnstat.c
> @@ -211,7 +211,7 @@ static struct table_hdr *build_hdr_string(struct lnstat_file *lnstat_files,
>   		ofs += width+1;
>   	}
>   	/* fill in spaces */
> -	for (h = 1; h <= th.num_lines; h++) {
> +	for (h = 1; h < th.num_lines; h++) {
>   		for (i = 0; i < ofs; i++) {
>   			if (th.hdr[h][i] == '\0')
>   				th.hdr[h][i] = ' ';
> --
> 2.27.0
>