From e8a1e7eaa19d0b757b06a2f913e3eeb4b1c002c6 Mon Sep 17 00:00:00 2001
From: Petr Mladek <pmladek@suse.com>
Date: Fri, 28 Nov 2025 14:59:19 +0100
Subject: [PATCH] kallsyms/ftrace: set module buildid in
 ftrace_mod_address_lookup()

__sprint_symbol() might access an invalid pointer when
kallsyms_lookup_buildid() returns a symbol found by
ftrace_mod_address_lookup().

The ftrace lookup function must set both @modname and @modbuildid the same
way as module_address_lookup().

Link: https://lkml.kernel.org/r/20251128135920.217303-7-pmladek@suse.com
Fixes: 9294523e3768 ("module: add printk formats to add module build ID to stacktraces")
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 include/linux/ftrace.h | 6 ++++--
 kernel/kallsyms.c      | 4 ++--
 kernel/trace/ftrace.c  | 5 ++++-
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index a3a8989e3268d..dc844d7e693d7 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -87,11 +87,13 @@ struct ftrace_hash;
 	defined(CONFIG_DYNAMIC_FTRACE)
 int
 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
-		   unsigned long *off, char **modname, char *sym);
+			  unsigned long *off, char **modname,
+			  const unsigned char **modbuildid, char *sym);
 #else
 static inline int
 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
-		   unsigned long *off, char **modname, char *sym)
+			  unsigned long *off, char **modname,
+			  const unsigned char **modbuildid, char *sym)
 {
 	return 0;
 }
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a37cafdf52cab..0f639c9073363 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -389,8 +389,8 @@ static int kallsyms_lookup_buildid(unsigned long addr,
 		ret = bpf_address_lookup(addr, symbolsize, offset, namebuf);
 
 	if (!ret)
-		ret = ftrace_mod_address_lookup(addr, symbolsize,
-						offset, modname, namebuf);
+		ret = ftrace_mod_address_lookup(addr, symbolsize, offset,
+						modname, modbuildid, namebuf);
 
 	return ret;
 }
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index aa758efc37314..304505c116868 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -7753,7 +7753,8 @@ ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
 
 int
 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
-		   unsigned long *off, char **modname, char *sym)
+			  unsigned long *off, char **modname,
+			  const unsigned char **modbuildid, char *sym)
 {
 	struct ftrace_mod_map *mod_map;
 	int ret = 0;
@@ -7765,6 +7766,8 @@ ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
 		if (ret) {
 			if (modname)
 				*modname = mod_map->mod->name;
+			if (modbuildid)
+				*modbuildid = module_buildid(mod_map->mod);
 			break;
 		}
 	}
-- 
2.47.3