tracing: Have option files inc the trace array ref count

commit 7e2cfbd2d3c86afcd5c26b5c4b1dd251f63c5838 upstream.

The option files update the options for a given trace array. For an
instance, if the file is opened and the instance is deleted, reading or
writing to the file will cause a use after free.

Up the ref count of the trace_array when an option file is opened.

Link: https://lkml.kernel.org/r/20230907024804.086679464@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Steven Rostedt (Google) 2023-09-06 22:47:15 -04:00 committed by Greg Kroah-Hartman
parent ff8cf370d3
commit 952e477f90

View File

@ -7996,12 +7996,33 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
return cnt;
}
static int tracing_open_options(struct inode *inode, struct file *filp)
{
struct trace_option_dentry *topt = inode->i_private;
int ret;
ret = tracing_check_open_get_tr(topt->tr);
if (ret)
return ret;
filp->private_data = inode->i_private;
return 0;
}
static int tracing_release_options(struct inode *inode, struct file *file)
{
struct trace_option_dentry *topt = file->private_data;
trace_array_put(topt->tr);
return 0;
}
static const struct file_operations trace_options_fops = {
.open = tracing_open_generic,
.open = tracing_open_options,
.read = trace_options_read,
.write = trace_options_write,
.llseek = generic_file_llseek,
.release = tracing_release_options,
};
/*