]> git.ipfire.org Git - thirdparty/linux.git/commit
tracing: Correct the refcount if the hist/hist_debug file fails to open
authorTengda Wu <wutengda@huaweicloud.com>
Fri, 14 Mar 2025 06:53:35 +0000 (06:53 +0000)
committerSteven Rostedt (Google) <rostedt@goodmis.org>
Fri, 14 Mar 2025 12:29:12 +0000 (08:29 -0400)
commit0b4ffbe4888a2c71185eaf5c1a02dd3586a9bc04
treec58e3d1473cfcfd0873f64c34fdc19471a161d60
parent7eb172143d5508b4da468ed59ee857c6e5e01da6
tracing: Correct the refcount if the hist/hist_debug file fails to open

The function event_{hist,hist_debug}_open() maintains the refcount of
'file->tr' and 'file' through tracing_open_file_tr(). However, it does
not roll back these counts on subsequent failure paths, resulting in a
refcount leak.

A very obvious case is that if the hist/hist_debug file belongs to a
specific instance, the refcount leak will prevent the deletion of that
instance, as it relies on the condition 'tr->ref == 1' within
__remove_instance().

Fix this by calling tracing_release_file_tr() on all failure paths in
event_{hist,hist_debug}_open() to correct the refcount.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Link: https://lore.kernel.org/20250314065335.1202817-1-wutengda@huaweicloud.com
Fixes: 1cc111b9cddc ("tracing: Fix uaf issue when open the hist or hist_debug file")
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
kernel/trace/trace_events_hist.c