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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2017-02-02 16:59:06 -0500 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2017-02-03 10:59:23 -0500 |
| commit | ae98d27afc3bde5a48f440d905317602a5cfb0d2 (patch) | |
| tree | 8b49f804b55c771a3e8f106438551fa79a700939 /kernel | |
| parent | d4ad9a1ccac31a04a32b5e7547b70428830e0218 (diff) | |
| download | linux-ae98d27afc3bde5a48f440d905317602a5cfb0d2.tar.gz linux-ae98d27afc3bde5a48f440d905317602a5cfb0d2.tar.xz | |
ftrace: Have set_graph_functions handle write with RDWR
Since reading the set_graph_functions uses seq functions, which sets the
file->private_data pointer to a seq_file descriptor. On writes the
ftrace_graph_data descriptor is set to file->private_data. But if the file
is opened for RDWR, the ftrace_graph_write() will incorrectly use the
file->private_data descriptor instead of
((struct seq_file *)file->private_data)->private pointer, and this can crash
the kernel.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b7df0dcf8652..0233c8cb45f4 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4842,6 +4842,12 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) return -ENOMEM; + /* Read mode uses seq functions */ + if (file->f_mode & FMODE_READ) { + struct seq_file *m = file->private_data; + fgd = m->private; + } + read = trace_get_user(&parser, ubuf, cnt, ppos); if (read >= 0 && trace_parser_loaded((&parser))) { |