[PATCH 2/2] proc: use generic setattr() for /proc/$PID/net

From: "Thomas Weißschuh" <linux@weissschuh.net>
To: Willy Tarreau <w@1wt.eu>, Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, "Zhangjin Wu" <falcon@tinylab.org>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Thomas Weißschuh" <linux@weissschuh.net>
Subject: [PATCH 2/2] proc: use generic setattr() for /proc/$PID/net
Date: Sat, 24 Jun 2023 12:30:47 +0200	[thread overview]
Message-ID: <20230624-proc-net-setattr-v1-2-73176812adee@weissschuh.net> (raw)
In-Reply-To: <20230624-proc-net-setattr-v1-0-73176812adee@weissschuh.net>

All other files in /proc/$PID/ use proc_setattr().

Not using it allows the usage of chmod() on /proc/$PID/net, even on
other processes owned by the same user.
The same would probably also be true for other attributes to be changed.

As this technically represents an ABI change it is not marked for
stable so any unlikely regressions are caught during a full release cycle.

Fixes: e9720acd728a ("[NET]: Make /proc/net a symlink on /proc/self/net (v3)")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 fs/proc/proc_net.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index a0c0419872e3..78f9e6b469c0 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -321,6 +321,7 @@ static int proc_tgid_net_getattr(struct mnt_idmap *idmap,
 const struct inode_operations proc_net_inode_operations = {
 	.lookup		= proc_tgid_net_lookup,
 	.getattr	= proc_tgid_net_getattr,
+	.setattr        = proc_setattr,
 };
 
 static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)

-- 
2.41.0

