From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757337Ab3FKU0c (ORCPT ); Tue, 11 Jun 2013 16:26:32 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41760 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756449Ab3FKUDZ (ORCPT ); Tue, 11 Jun 2013 16:03:25 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Namhyung Kim , Frederic Weisbecker , Ingo Molnar , Namhyung Kim , Steven Rostedt , Li Zefan Subject: [ 31/32] tracing: Fix possible NULL pointer dereferences Date: Tue, 11 Jun 2013 13:03:30 -0700 Message-Id: <20130611200130.282963163@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.254.g5578ad7 In-Reply-To: <20130611200126.214442788@linuxfoundation.org> References: <20130611200126.214442788@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namhyung Kim commit 6a76f8c0ab19f215af2a3442870eeb5f0e81998d upstream. Currently set_ftrace_pid and set_graph_function files use seq_lseek for their fops. However seq_open() is called only for FMODE_READ in the fops->open() so that if an user tries to seek one of those file when she open it for writing, it sees NULL seq_file and then panic. It can be easily reproduced with following command: $ cd /sys/kernel/debug/tracing $ echo 1234 | sudo tee -a set_ftrace_pid In this example, GNU coreutils' tee opens the file with fopen(, "a") and then the fopen() internally calls lseek(). Link: http://lkml.kernel.org/r/1365663302-2170-1-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Signed-off-by: Steven Rostedt [ lizf: adjust context ] Signed-off-by: Li Zefan Signed-off-by: Greg Kroah-Hartman --- include/linux/ftrace.h | 2 +- kernel/trace/ftrace.c | 10 +++++----- kernel/trace/trace_stack.c | 2 +- 3 files changed, 7 insertions(+), 7 deletions(-) --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -299,7 +299,7 @@ ssize_t ftrace_filter_write(struct file size_t cnt, loff_t *ppos); ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos); -loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin); +loff_t ftrace_filter_lseek(struct file *file, loff_t offset, int origin); int ftrace_regex_release(struct inode *inode, struct file *file); void __init --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2626,7 +2626,7 @@ ftrace_notrace_open(struct inode *inode, } loff_t -ftrace_regex_lseek(struct file *file, loff_t offset, int origin) +ftrace_filter_lseek(struct file *file, loff_t offset, int origin) { loff_t ret; @@ -3445,7 +3445,7 @@ static const struct file_operations ftra .open = ftrace_filter_open, .read = seq_read, .write = ftrace_filter_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; @@ -3453,7 +3453,7 @@ static const struct file_operations ftra .open = ftrace_notrace_open, .read = seq_read, .write = ftrace_notrace_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; @@ -3659,8 +3659,8 @@ static const struct file_operations ftra .open = ftrace_graph_open, .read = seq_read, .write = ftrace_graph_write, + .llseek = ftrace_filter_lseek, .release = ftrace_graph_release, - .llseek = seq_lseek, }; #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ @@ -4261,7 +4261,7 @@ static const struct file_operations ftra .open = ftrace_pid_open, .write = ftrace_pid_write, .read = seq_read, - .llseek = seq_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_pid_release, }; --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -384,7 +384,7 @@ static const struct file_operations stac .open = stack_trace_filter_open, .read = seq_read, .write = ftrace_filter_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, };