From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: (unknown) Date: Fri, 13 Nov 2009 14:35:44 +0800 Message-ID: <20091113063544.GA28859@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: LKML , "Yin, Kangkai" , netdev@vger.kernel.org To: Patrick McHardy Return-path: Received: from mga14.intel.com ([143.182.124.37]:56011 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753463AbZKMGfm (ORCPT ); Fri, 13 Nov 2009 01:35:42 -0500 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: netfilter: nf_log: fix sleeping function called from invalid context in seq_show() [ 171.925285] BUG: sleeping function called from invalid context at kernel/mutex.c:280 [ 171.925296] in_atomic(): 1, irqs_disabled(): 0, pid: 671, name: grep [ 171.925306] 2 locks held by grep/671: [ 171.925312] #0: (&p->lock){+.+.+.}, at: [] seq_read+0x25/0x36c [ 171.925340] #1: (rcu_read_lock){.+.+..}, at: [] seq_start+0x0/0x44 [ 171.925372] Pid: 671, comm: grep Not tainted 2.6.31.6-4-netbook #3 [ 171.925380] Call Trace: [ 171.925398] [] ? __debug_show_held_locks+0x1e/0x20 [ 171.925414] [] __might_sleep+0xfb/0x102 [ 171.925430] [] mutex_lock_nested+0x1c/0x2ad [ 171.925444] [] seq_show+0x74/0x127 [ 171.925456] [] seq_read+0x1b4/0x36c [ 171.925469] [] ? seq_read+0x0/0x36c [ 171.925483] [] proc_reg_read+0x60/0x74 [ 171.925496] [] ? proc_reg_read+0x0/0x74 [ 171.925510] [] vfs_read+0x87/0x110 [ 171.925523] [] sys_read+0x3b/0x60 [ 171.925538] [] syscall_call+0x7/0xb Fix it by replacing RCU with nf_log_mutex. CC: Patrick McHardy Reported-by: "Yin, Kangkai" Signed-off-by: Wu Fengguang --- net/netfilter/nf_log.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) --- sound-2.6.orig/net/netfilter/nf_log.c 2009-11-13 13:47:14.000000000 +0800 +++ sound-2.6/net/netfilter/nf_log.c 2009-11-13 13:49:23.000000000 +0800 @@ -128,9 +128,8 @@ EXPORT_SYMBOL(nf_log_packet); #ifdef CONFIG_PROC_FS static void *seq_start(struct seq_file *seq, loff_t *pos) - __acquires(RCU) { - rcu_read_lock(); + mutex_lock(&nf_log_mutex); if (*pos >= ARRAY_SIZE(nf_loggers)) return NULL; @@ -149,9 +148,8 @@ static void *seq_next(struct seq_file *s } static void seq_stop(struct seq_file *s, void *v) - __releases(RCU) { - rcu_read_unlock(); + mutex_unlock(&nf_log_mutex); } static int seq_show(struct seq_file *s, void *v) @@ -161,7 +159,7 @@ static int seq_show(struct seq_file *s, struct nf_logger *t; int ret; - logger = rcu_dereference(nf_loggers[*pos]); + logger = nf_loggers[*pos]; if (!logger) ret = seq_printf(s, "%2lld NONE (", *pos); @@ -171,22 +169,16 @@ static int seq_show(struct seq_file *s, if (ret < 0) return ret; - mutex_lock(&nf_log_mutex); list_for_each_entry(t, &nf_loggers_l[*pos], list[*pos]) { ret = seq_printf(s, "%s", t->name); - if (ret < 0) { - mutex_unlock(&nf_log_mutex); + if (ret < 0) return ret; - } if (&t->list[*pos] != nf_loggers_l[*pos].prev) { ret = seq_printf(s, ","); - if (ret < 0) { - mutex_unlock(&nf_log_mutex); + if (ret < 0) return ret; - } } } - mutex_unlock(&nf_log_mutex); return seq_printf(s, ")\n"); }