Commit b2aa3b4d64e4 for kernel

commit b2aa3b4d64e460ac606f386c24e7d8a873ce6f1a
Author: Steven Rostedt <rostedt@goodmis.org>
Date:   Tue Apr 28 12:23:02 2026 -0400

    tracing/probes: Limit size of event probe to 3K

    There currently isn't a max limit an event probe can be. One could make an
    event greater than PAGE_SIZE, which makes the event useless because if
    it's bigger than the max event that can be recorded into the ring buffer,
    then it will never be recorded.

    A event probe should never need to be greater than 3K, so make that the
    max size. As long as the max is less than the max that can be recorded
    onto the ring buffer, it should be fine.

    Cc: stable@vger.kernel.org
    Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
    Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
    Fixes: 93ccae7a22274 ("tracing/kprobes: Support basic types on dynamic events")
    Link: https://patch.msgid.link/20260428122302.706610ba@gandalf.local.home
    Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index e1c73065dae5..e0d3a0da26af 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1523,6 +1523,12 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 	parg->offset = *size;
 	*size += parg->type->size * (parg->count ?: 1);

+	if (*size > MAX_PROBE_EVENT_SIZE) {
+		ret = -E2BIG;
+		trace_probe_log_err(ctx->offset, EVENT_TOO_BIG);
+		goto fail;
+	}
+
 	if (parg->count) {
 		len = strlen(parg->type->fmttype) + 6;
 		parg->fmt = kmalloc(len, GFP_KERNEL);
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 9fc56c937130..262d8707a3df 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -38,6 +38,7 @@
 #define MAX_BTF_ARGS_LEN	128
 #define MAX_DENTRY_ARGS_LEN	256
 #define MAX_STRING_SIZE		PATH_MAX
+#define MAX_PROBE_EVENT_SIZE	3072

 /* Reserved field names */
 #define FIELD_STRING_IP		"__probe_ip"
@@ -561,7 +562,8 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 	C(BAD_TYPE4STR,		"This type does not fit for string."),\
 	C(NEED_STRING_TYPE,	"$comm and immediate-string only accepts string type"),\
 	C(TOO_MANY_ARGS,	"Too many arguments are specified"),	\
-	C(TOO_MANY_EARGS,	"Too many entry arguments specified"),
+	C(TOO_MANY_EARGS,	"Too many entry arguments specified"),	\
+	C(EVENT_TOO_BIG,	"Event too big (too many fields?)"),

 #undef C
 #define C(a, b)		TP_ERR_##a