From d8d17d2bf6181cdc9b8ef3db862006ddb6af12d4 Mon Sep 17 00:00:00 2001 From: Michael Tokarev Date: Mon, 30 Dec 2024 00:08:50 +0300 Subject: [PATCH] Revert "vvfat: fix ubsan issue in create_long_filename" MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This reverts commit 0cb3ff7c22671aa1e1e227318799ccf6762c3bea. The original code was right in that long name in LFN directory entry uses other parts of the entry for the name too, not just the original "name" field. So it is wrong to limit the offset to be within the name field. Some other mechanism is needed to fix the ubsan report and whole messy usage of bytes past the given field. Reported-by: Volker Rümelin Signed-off-by: Michael Tokarev --- block/vvfat.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/block/vvfat.c b/block/vvfat.c index f2eafaa923..8ffe8b3b9b 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -426,10 +426,6 @@ static direntry_t *create_long_filename(BDRVVVFATState *s, const char *filename) else if(offset<22) offset=14+offset-10; else offset=28+offset-22; entry=array_get(&(s->directory),s->directory.next-1-(i/26)); - /* ensure we don't write anything past entry->name */ - if (offset >= sizeof(entry->name)) { - continue; - } if (i >= 2 * length + 2) { entry->name[offset] = 0xff; } else if (i % 2 == 0) { -- 2.30.2