Davidlohr Bueso wrote: > When verifying GPT header integrity, make sure that > first usable LBA is smaller than last usable LBA. > --- > libparted/labels/gpt.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c > index 6032e3f..6dfaf3e 100644 > --- a/libparted/labels/gpt.c > +++ b/libparted/labels/gpt.c > @@ -650,6 +650,11 @@ _header_is_valid (PedDisk const *disk, > GuidPartitionTableHeader_t *gpt, > return 0; > > PedSector first_usable = PED_LE64_TO_CPU (gpt->FirstUsableLBA); > + PedSector last_usable = PED_LE64_TO_CPU (gpt->LastUsableLBA); > + > + if (last_usable < first_usable) > + return 0; > + > if (first_usable < 3) > return 0;
Thank you for the patch. That is an improvement. Normally I would require a test that exercises this new code, (the bar for GPT is particularly high) but I don't have time to write it now, and it wouldn't be fair to ask you to do it. I've made a minor correctness change to the log (s/smaller/no larger than/) since they may be equal. >From 46d9108009ccb9ac567cc285a15efb05864932d5 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso <[email protected]> Date: Tue, 11 Sep 2012 19:22:32 +0200 Subject: [PATCH] gpt: require first_usable_LBA <= last_usable_LBA When verifying GPT header integrity, ensure that the first usable LBA is no larger than the last usable LBA. * libparted/labels/gpt.c (_header_is_valid): Reject a header with last_usable < first_usable. --- libparted/labels/gpt.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c index 6032e3f..83e518f 100644 --- a/libparted/labels/gpt.c +++ b/libparted/labels/gpt.c @@ -653,6 +653,10 @@ _header_is_valid (PedDisk const *disk, GuidPartitionTableHeader_t *gpt, if (first_usable < 3) return 0; + PedSector last_usable = PED_LE64_TO_CPU (gpt->LastUsableLBA); + if (last_usable < first_usable) + return 0; + origcrc = gpt->HeaderCRC32; gpt->HeaderCRC32 = 0; if (pth_crc32 (dev, gpt, &crc) != 0) -- 1.7.12.363.g53284de
