From 00d69986da83a74f6f5731c80f8dd09fde95d19a Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 22 Jun 2020 16:03:55 -0500 Subject: [PATCH] nbd: Avoid off-by-one in long export name truncation When snprintf returns the same value as the buffer size, the final byte was truncated to ensure a NUL terminator. Fortunately, such long export names are unusual enough, with no real impact other than what is displayed to the user. Fixes: 5c86bdf12089 Reported-by: Max Reitz Signed-off-by: Eric Blake Message-Id: <20200622210355.414941-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy --- block/nbd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/nbd.c b/block/nbd.c index c297336ffc5..65a4f56924e 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -2002,7 +2002,7 @@ static void nbd_refresh_filename(BlockDriverState *bs) len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nbd://%s:%s", host, port); } - if (len > sizeof(bs->exact_filename)) { + if (len >= sizeof(bs->exact_filename)) { /* Name is too long to represent exactly, so leave it empty. */ bs->exact_filename[0] = '\0'; } -- 2.39.5