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Commit 952e477f authored by Steven Rostedt (Google)'s avatar Steven Rostedt (Google) Committed by Greg Kroah-Hartman
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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: 8530dec6 ("tracing: Add tracing_check_open_get_tr()")
Tested-by: default avatarLinux Kernel Functional Testing <lkft@linaro.org>
Tested-by: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ff8cf370

kernel/trace/trace.c

+22 −1
Original line number Diff line number Diff line
@@ -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,

};



/*