linux-kernel - [PATCH 2/3] 9p: fix /sys/fs/9p/caches overwriting itself

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20250926-v9fs_misc-v1-2-a8b3907fc04d@codewreck.org>
Date: Fri, 26 Sep 2025 18:27:30 +0900
From: Dominique Martinet via B4 Relay <devnull+asmadeus.codewreck.org@...nel.org>
To: "Randall P. Embry" <rpembry@...il.com>, 
 Eric Van Hensbergen <ericvh@...nel.org>, 
 Latchesar Ionkov <lucho@...kov.net>, 
 Christian Schoenebeck <linux_oss@...debyte.com>
Cc: v9fs@...ts.linux.dev, linux-kernel@...r.kernel.org, 
 Dominique Martinet <asmadeus@...ewreck.org>
Subject: [PATCH 2/3] 9p: fix /sys/fs/9p/caches overwriting itself

From: "Randall P. Embry" <rpembry@...il.com>

caches_show() overwrote its buffer on each iteration,
so only the last cache tag was visible in sysfs output.

Properly append with snprintf(buf + count, …).

Signed-off-by: Randall P. Embry <rpembry@...il.com>
Signed-off-by: Dominique Martinet <asmadeus@...ewreck.org>
---
 fs/9p/v9fs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 01e70a464b6039231df272e43b4ebdd3b5afb967..4d289c56578fb15e45d8e94a264977898973cb31 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -560,7 +560,7 @@ static ssize_t caches_show(struct kobject *kobj,
 	spin_lock(&v9fs_sessionlist_lock);
 	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
 		if (v9ses->cachetag) {
-			n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
+			n = snprintf(buf + count, limit, "%s\n", v9ses->cachetag);
 			if (n < 0) {
 				count = n;
 				break;

-- 
2.51.0