From: David Ahern <dsahern@kernel.org>
To: netdev@vger.kernel.org, kuba@kernel.org, davem@davemloft.net
Cc: ciorneiioana@gmail.com, David Ahern <dsahern@kernel.org>,
Yajun Deng <yajun.deng@linux.dev>
Subject: [PATCH net-next] ipv4: Fix refcount warning for new fib_info
Date: Mon, 2 Aug 2021 10:02:21 -0600 [thread overview]
Message-ID: <20210802160221.27263-1-dsahern@kernel.org> (raw)
Ioana reported a refcount warning when booting over NFS:
[ 5.042532] ------------[ cut here ]------------
[ 5.047184] refcount_t: addition on 0; use-after-free.
[ 5.052324] WARNING: CPU: 7 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0xa4/0x150
...
[ 5.167201] Call trace:
[ 5.169635] refcount_warn_saturate+0xa4/0x150
[ 5.174067] fib_create_info+0xc00/0xc90
[ 5.177982] fib_table_insert+0x8c/0x620
[ 5.181893] fib_magic.isra.0+0x110/0x11c
[ 5.185891] fib_add_ifaddr+0xb8/0x190
[ 5.189629] fib_inetaddr_event+0x8c/0x140
fib_treeref needs to be set after kzalloc. The old code had a ++ which
led to the confusion when the int was replaced by a refcount_t.
Fixes: 79976892f7ea ("net: convert fib_treeref from int to refcount_t")
Signed-off-by: David Ahern <dsahern@kernel.org>
Reported-by: Ioana Ciornei <ciorneiioana@gmail.com>
Cc: Yajun Deng <yajun.deng@linux.dev>
---
net/ipv4/fib_semantics.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index fa19f4cdf3a4..f29feb7772da 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1551,7 +1551,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
return ofi;
}
- refcount_inc(&fi->fib_treeref);
+ refcount_set(&fi->fib_treeref, 1);
refcount_set(&fi->fib_clntref, 1);
spin_lock_bh(&fib_info_lock);
hlist_add_head(&fi->fib_hash,
--
2.24.3 (Apple Git-128)
next reply other threads:[~2021-08-02 16:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-02 16:02 David Ahern [this message]
2021-08-02 17:58 ` [PATCH net-next] ipv4: Fix refcount warning for new fib_info Matthieu Baerts
2021-08-02 18:04 ` David Ahern
2021-08-02 20:20 ` Jakub Kicinski
2021-08-03 7:39 ` yajun.deng
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