Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934592Ab3DOCop (ORCPT ); Sun, 14 Apr 2013 22:44:45 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36539 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934471Ab3DOCoI (ORCPT ); Sun, 14 Apr 2013 22:44:08 -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 Subject: [ 21/27] tracing: Fix possible NULL pointer dereferences Date: Sun, 14 Apr 2013 19:43:20 -0700 Message-Id: <20130415024232.926555500@linuxfoundation.org> X-Mailer: git-send-email 1.8.2.1.368.g99c2266 In-Reply-To: <20130415024231.351969241@linuxfoundation.org> References: <20130415024231.351969241@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3671 Lines: 114 3.8-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 Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt 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 @@ -394,7 +394,7 @@ 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 whence); +loff_t ftrace_filter_lseek(struct file *file, loff_t offset, int whence); int ftrace_regex_release(struct inode *inode, struct file *file); void __init --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2674,7 +2674,7 @@ ftrace_notrace_open(struct inode *inode, } loff_t -ftrace_regex_lseek(struct file *file, loff_t offset, int whence) +ftrace_filter_lseek(struct file *file, loff_t offset, int whence) { loff_t ret; @@ -3548,7 +3548,7 @@ 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, }; @@ -3556,7 +3556,7 @@ 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, }; @@ -3761,8 +3761,8 @@ 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 */ @@ -4420,7 +4420,7 @@ 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 @@ -322,7 +322,7 @@ 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, }; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/