diff options
| author | Namhyung Kim <namhyung.kim@lge.com> | 2013-06-07 17:01:16 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-06-13 09:45:03 -0700 |
| commit | 3a22cc7f184b77731816e55662cd12f0c3d24d56 (patch) | |
| tree | ce3612a4ea2ec1ed53d5c98a24b88aa80067129c /kernel/trace/trace_stack.c | |
| parent | ce840e2f7825bfd240782dc209c2f2b8db514287 (diff) | |
tracing: Fix possible NULL pointer dereferences
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 <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[ lizf: adjust context ]
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace/trace_stack.c')
| -rw-r--r-- | kernel/trace/trace_stack.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index c70f6bfbb732..8298997c2486 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -384,7 +384,7 @@ 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, }; |