From 8e7d178d06e8937454b6d2f2811fa6a15656a214 Mon Sep 17 00:00:00 2001 From: Thorsten Blum Date: Wed, 6 Aug 2025 03:03:49 +0200 Subject: [PATCH] smb: server: Fix extension string in ksmbd_extract_shortname() In ksmbd_extract_shortname(), strscpy() is incorrectly called with the length of the source string (excluding the NUL terminator) rather than the size of the destination buffer. This results in "__" being copied to 'extension' rather than "___" (two underscores instead of three). Use the destination buffer size instead to ensure that the string "___" (three underscores) is copied correctly. Cc: stable@vger.kernel.org Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Signed-off-by: Thorsten Blum Acked-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/smb_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c index 425c756bcfb8..b23203a1c286 100644 --- a/fs/smb/server/smb_common.c +++ b/fs/smb/server/smb_common.c @@ -515,7 +515,7 @@ int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname, p = strrchr(longname, '.'); if (p == longname) { /*name starts with a dot*/ - strscpy(extension, "___", strlen("___")); + strscpy(extension, "___", sizeof(extension)); } else { if (p) { p++; -- 2.47.2