From 457965c13f0837a289c9164b842d0860133f6274 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 5 Mar 2026 11:33:39 -0800 Subject: [PATCH 1/3] tracing: Add NULL pointer check to trigger_data_free() If trigger_data_alloc() fails and returns NULL, event_hist_trigger_parse() jumps to the out_free error path. While kfree() safely handles a NULL pointer, trigger_data_free() does not. This causes a NULL pointer dereference in trigger_data_free() when evaluating data->cmd_ops->set_filter. Fix the problem by adding a NULL pointer check to trigger_data_free(). The problem was found by an experimental code review agent based on gemini-3.1-pro while reviewing backports into v6.18.y. Cc: Miaoqian Lin Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Steven Rostedt (Google) Link: https://patch.msgid.link/20260305193339.2810953-1-linux@roeck-us.net Fixes: 0550069cc25f ("tracing: Properly process error handling in event_hist_trigger_parse()") Assisted-by: Gemini:gemini-3.1-pro Signed-off-by: Guenter Roeck Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_trigger.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index fecbd679d432..d5230b759a2d 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -50,6 +50,9 @@ static int trigger_kthread_fn(void *ignore) void trigger_data_free(struct event_trigger_data *data) { + if (!data) + return; + if (data->cmd_ops->set_filter) data->cmd_ops->set_filter(NULL, data, NULL); From 3b1679e086bb869ca02722f6bd29b3573a6a0e7e Mon Sep 17 00:00:00 2001 From: Andrei-Alexandru Tachici Date: Mon, 2 Mar 2026 11:27:34 +0100 Subject: [PATCH 2/3] tracing: Fix enabling multiple events on the kernel command line and bootconfig Multiple events can be enabled on the kernel command line via a comma separator. But if the are specified one at a time, then only the last event is enabled. This is because the event names are saved in a temporary buffer, and each call by the init cmdline code will reset that buffer. This also affects names in the boot config file, as it may call the callback multiple times with an example of: kernel.trace_event = ":mod:rproc_qcom_common", ":mod:qrtr", ":mod:qcom_aoss" Change the cmdline callback function to append a comma and the next value if the temporary buffer already has content. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://patch.msgid.link/20260302-trace-events-allow-multiple-modules-v1-1-ce4436e37fb8@oss.qualcomm.com Signed-off-by: Andrei-Alexandru Tachici Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index b7343fdfd7b0..249d1cba72c0 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -4493,7 +4493,11 @@ static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; static __init int setup_trace_event(char *str) { - strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE); + if (bootup_event_buf[0] != '\0') + strlcat(bootup_event_buf, ",", COMMAND_LINE_SIZE); + + strlcat(bootup_event_buf, str, COMMAND_LINE_SIZE); + trace_set_ring_buffer_expanded(NULL); disable_tracing_selftest("running event tracing"); From d008ba8be8984760e36d7dcd4adbd5a41a645708 Mon Sep 17 00:00:00 2001 From: Calvin Owens Date: Fri, 6 Mar 2026 19:19:25 -0800 Subject: [PATCH 3/3] tracing: Fix trace_buf_size= cmdline parameter with sizes >= 2G Some of the sizing logic through tracer_alloc_buffers() uses int internally, causing unexpected behavior if the user passes a value that does not fit in an int (on my x86 machine, the result is uselessly tiny buffers). Fix by plumbing the parameter's real type (unsigned long) through to the ring buffer allocation functions, which already use unsigned long. It has always been possible to create larger ring buffers via the sysfs interface: this only affects the cmdline parameter. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://patch.msgid.link/bff42a4288aada08bdf74da3f5b67a2c28b761f8.1772852067.git.calvin@wbinvd.org Fixes: 73c5162aa362 ("tracing: keep ring buffer to minimum size till used") Signed-off-by: Calvin Owens Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1e7c032a72d2..ebd996f8710e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9350,7 +9350,7 @@ static void setup_trace_scratch(struct trace_array *tr, } static int -allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size) +allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, unsigned long size) { enum ring_buffer_flags rb_flags; struct trace_scratch *tscratch; @@ -9405,7 +9405,7 @@ static void free_trace_buffer(struct array_buffer *buf) } } -static int allocate_trace_buffers(struct trace_array *tr, int size) +static int allocate_trace_buffers(struct trace_array *tr, unsigned long size) { int ret; @@ -10769,7 +10769,7 @@ __init static void enable_instances(void) __init static int tracer_alloc_buffers(void) { - int ring_buf_size; + unsigned long ring_buf_size; int ret = -ENOMEM;