diff options
| author | Petr Pavlu <petr.pavlu@suse.com> | 2026-02-19 17:27:01 +0100 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-04 07:21:20 -0500 |
| commit | e4e5026252b4e03c0f31511b2de97d0ec6ffb7aa (patch) | |
| tree | 10b30853c7edd181917223e05d3a25a0fc8201ae | |
| parent | ad058a4317db7fdb3f09caa6ed536d24a62ce6a0 (diff) | |
tracing: Fix checking of freed trace_event_file for hist files
[ Upstream commit f0a0da1f907e8488826d91c465f7967a56a95aca ]
The event_hist_open() and event_hist_poll() functions currently retrieve
a trace_event_file pointer from a file struct by invoking
event_file_data(), which simply returns file->f_inode->i_private. The
functions then check if the pointer is NULL to determine whether the event
is still valid. This approach is flawed because i_private is assigned when
an eventfs inode is allocated and remains set throughout its lifetime.
Instead, the code should call event_file_file(), which checks for
EVENT_FILE_FL_FREED. Using the incorrect access function may result in the
code potentially opening a hist file for an event that is being removed or
becoming stuck while polling on this file.
Correct the access method to event_file_file() in both functions.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20260219162737.314231-2-petr.pavlu@suse.com
Fixes: 1bd13edbbed6 ("tracing/hist: Add poll(POLLIN) support on hist file")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/trace/trace_events_hist.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index ad203155855a..19b3d388fbc6 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5760,7 +5760,7 @@ static __poll_t event_hist_poll(struct file *file, struct poll_table_struct *wai guard(mutex)(&event_mutex); - event_file = event_file_data(file); + event_file = event_file_file(file); if (!event_file) return EPOLLERR; @@ -5798,7 +5798,7 @@ static int event_hist_open(struct inode *inode, struct file *file) guard(mutex)(&event_mutex); - event_file = event_file_data(file); + event_file = event_file_file(file); if (!event_file) { ret = -ENODEV; goto err; |