From: Thorsten Blum <thorsten.blum@linux.dev>
Date: Wed, 1 Apr 2026 15:20:40 +0000 (+0200)
Subject: exec: use strnlen() in __set_task_comm
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10cd6758e054e4002ccb409fef7dd2c6b7bbd549;p=thirdparty%2Fkernel%2Flinux.git

exec: use strnlen() in __set_task_comm

Use strnlen() to limit source string scanning to 'TASK_COMM_LEN - 1'
bytes.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260401152039.724811-3-thorsten.blum@linux.dev
Signed-off-by: Kees Cook <kees@kernel.org>
---

diff --git a/fs/exec.c b/fs/exec.c
index 9ea3a775d51e9..ba12b4c466f6d 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1074,7 +1074,7 @@ static int unshare_sighand(struct task_struct *me)
  */
 void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
 {
-	size_t len = min(strlen(buf), sizeof(tsk->comm) - 1);
+	size_t len = strnlen(buf, sizeof(tsk->comm) - 1);
 
 	trace_task_rename(tsk, buf);
 	memcpy(tsk->comm, buf, len);