diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2025-06-10 09:33:48 -0400 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2025-06-10 09:39:58 -0400 |
| commit | 8a157d8a00e815cab4432653cb50c9cedbbb4931 (patch) | |
| tree | e282d839bf33bf2a74184f2f035ca344dbd6f345 | |
| parent | 19272b37aa4f83ca52bdf9c16d5d81bdd1354494 (diff) | |
tracing: Do not free "head" on error path of filter_free_subsystem_filters()
The variable "head" is allocated and initialized as a list before
allocating the first "item" for the list. If the allocation of "item"
fails, it frees "head" and then jumps to the label "free_now" which will
process head and free it.
This will cause a UAF of "head", and it doesn't need to free it before
jumping to the "free_now" label as that code will free it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250610093348.33c5643a@gandalf.local.home
Fixes: a9d0aab5eb33 ("tracing: Fix regression of filter waiting a long time on RCU synchronization")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202506070424.lCiNreTI-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace_events_filter.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index ea8b364b6818..08141f105c95 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1437,10 +1437,8 @@ static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir, INIT_LIST_HEAD(&head->list); item = kmalloc(sizeof(*item), GFP_KERNEL); - if (!item) { - kfree(head); + if (!item) goto free_now; - } item->filter = filter; list_add_tail(&item->list, &head->list); |