Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966970Ab3DRJVx (ORCPT ); Thu, 18 Apr 2013 05:21:53 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:40313 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759328Ab3DRJS3 (ORCPT ); Thu, 18 Apr 2013 05:18:29 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Frederic Weisbecker , Ingo Molnar , Namhyung Kim , Namhyung Kim , Steven Rostedt , Luis Henriques Subject: [PATCH 60/72] tracing: Fix possible NULL pointer dereferences Date: Thu, 18 Apr 2013 10:16:45 +0100 Message-Id: <1366276617-3553-61-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1366276617-3553-1-git-send-email-luis.henriques@canonical.com> References: <1366276617-3553-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4099 Lines: 120 3.5.7.11 -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 Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Signed-off-by: Namhyung Kim Signed-off-by: Steven Rostedt [ luis: adjust context ] Signed-off-by: Luis Henriques --- include/linux/ftrace.h | 2 +- kernel/trace/ftrace.c | 10 +++++----- kernel/trace/trace_stack.c | 2 +- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 55e6d63..6ce7928 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -305,7 +305,7 @@ ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 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 diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7da46c7..f125532 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2594,7 +2594,7 @@ ftrace_notrace_open(struct inode *inode, struct file *file) } 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; @@ -3413,7 +3413,7 @@ static const struct file_operations ftrace_filter_fops = { .open = ftrace_filter_open, .read = seq_read, .write = ftrace_filter_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; @@ -3421,7 +3421,7 @@ static const struct file_operations ftrace_notrace_fops = { .open = ftrace_notrace_open, .read = seq_read, .write = ftrace_notrace_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; @@ -3626,8 +3626,8 @@ static const struct file_operations ftrace_graph_fops = { .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 */ @@ -4254,7 +4254,7 @@ static const struct file_operations ftrace_pid_fops = { .open = ftrace_pid_open, .write = ftrace_pid_write, .read = seq_read, - .llseek = seq_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_pid_release, }; diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index d4545f4..aa4270a 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -324,7 +324,7 @@ static const struct file_operations stack_trace_filter_fops = { .open = stack_trace_filter_open, .read = seq_read, .write = ftrace_filter_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; -- 1.8.1.2 -- 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/