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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        syzbot+e820fdc8ce362f2dea51@syzkaller.appspotmail.com,
        Jon Maloy <jmaloy@redhat.com>,
        Hoang Le <hoang.h.le@dektech.com.au>,
        Jakub Kicinski <kuba@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 335/411] tipc: check attribute length for bearer name
Date:   Mon, 13 Jun 2022 12:10:08 +0200
Message-Id: <20220613094938.765432242@linuxfoundation.org>
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From: Hoang Le <hoang.h.le@dektech.com.au>

[ Upstream commit 7f36f798f89bf32c0164049cb0e3fd1af613d0bb ]

syzbot reported uninit-value:
=====================================================
BUG: KMSAN: uninit-value in string_nocheck lib/vsprintf.c:644 [inline]
BUG: KMSAN: uninit-value in string+0x4f9/0x6f0 lib/vsprintf.c:725
 string_nocheck lib/vsprintf.c:644 [inline]
 string+0x4f9/0x6f0 lib/vsprintf.c:725
 vsnprintf+0x2222/0x3650 lib/vsprintf.c:2806
 vprintk_store+0x537/0x2150 kernel/printk/printk.c:2158
 vprintk_emit+0x28b/0xab0 kernel/printk/printk.c:2256
 vprintk_default+0x86/0xa0 kernel/printk/printk.c:2283
 vprintk+0x15f/0x180 kernel/printk/printk_safe.c:50
 _printk+0x18d/0x1cf kernel/printk/printk.c:2293
 tipc_enable_bearer net/tipc/bearer.c:371 [inline]
 __tipc_nl_bearer_enable+0x2022/0x22a0 net/tipc/bearer.c:1033
 tipc_nl_bearer_enable+0x6c/0xb0 net/tipc/bearer.c:1042
 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline]

- Do sanity check the attribute length for TIPC_NLA_BEARER_NAME.
- Do not use 'illegal name' in printing message.

Reported-by: syzbot+e820fdc8ce362f2dea51@syzkaller.appspotmail.com
Fixes: cb30a63384bc ("tipc: refactor function tipc_enable_bearer()")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Link: https://lore.kernel.org/r/20220602063053.5892-1-hoang.h.le@dektech.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/tipc/bearer.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 8bd2454cc89d..577f71dd63fb 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -248,9 +248,8 @@ static int tipc_enable_bearer(struct net *net, const char *name,
 	u32 i;
 
 	if (!bearer_name_validate(name, &b_names)) {
-		errstr = "illegal name";
 		NL_SET_ERR_MSG(extack, "Illegal name");
-		goto rejected;
+		return res;
 	}
 
 	if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
-- 
2.35.1