From mboxrd@z Thu Jan 1 00:00:00 1970 From: zkabelac@sourceware.org Date: 30 Mar 2011 12:30:40 -0000 Subject: LVM2 ./WHATS_NEW lib/format1/import-extents.c Message-ID: <20110330123040.30920.qmail@sourceware.org> List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit CVSROOT: /cvs/lvm2 Module name: LVM2 Changes by: zkabelac at sourceware.org 2011-03-30 12:30:40 Modified files: . : WHATS_NEW lib/format1 : import-extents.c Log message: Fix reading of unitialized memory Could be reached via few of our lvm2 test cases: ==11501== Invalid read of size 8 ==11501== at 0x49B2E0: _area_length (import-extents.c:204) ==11501== by 0x49B40C: _read_linear (import-extents.c:222) ==11501== by 0x49B952: _build_segments (import-extents.c:323) ==11501== by 0x49B9A0: _build_all_segments (import-extents.c:334) ==11501== by 0x49BB4C: import_extents (import-extents.c:364) ==11501== by 0x497655: _format1_vg_read (format1.c:217) ==11501== by 0x47E43E: _vg_read (metadata.c:2901) cut from t-vgcvgbackup-usage.sh -- pvcreate -M1 $(cat DEVICES) vgcreate -M1 -c n $vg $(cat DEVICES) lvcreate -l1 -n $lv1 $vg $dev1 -- Idea of the fix is rather defensive - to allocate one extra element to 'map' array which is then used in _area_length() - where the loop checks, whether next map entry is continuous. By placing there always one extra zero entry - we fix the read of unallocated memory, and we make sure the data would not make a continous block. FIXME: there could be a problem if some special broken lvm1 data would be imported. As the format1 is currently not really used - leave it for future fix and use this small hotfix for now. Patches: http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW.diff?cvsroot=lvm2&r1=1.1962&r2=1.1963 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/format1/import-extents.c.diff?cvsroot=lvm2&r1=1.39&r2=1.40 --- LVM2/WHATS_NEW 2011/03/29 21:57:56 1.1962 +++ LVM2/WHATS_NEW 2011/03/30 12:30:39 1.1963 @@ -1,5 +1,6 @@ Version 2.02.85 - =================================== + Fix reading of unallocated memory in lvm1 format import function. Replace several strncmp() calls with id_equal(). Fix lvmcache_info transfer to orphan_vginfo in _lvmcache_update_vgname(). Fix -Wold-style-definition gcc warnings. --- LVM2/lib/format1/import-extents.c 2010/04/08 00:28:57 1.39 +++ LVM2/lib/format1/import-extents.c 2011/03/30 12:30:39 1.40 @@ -63,8 +63,12 @@ goto_bad; lvm->lv = ll->lv; + /* + * Alloc 1 extra element, so the loop in _area_length() and + * _check_stripe() finds the last map member as noncontinuous. + */ if (!(lvm->map = dm_pool_zalloc(mem, sizeof(*lvm->map) - * ll->lv->le_count))) + * (ll->lv->le_count + 1)))) goto_bad; if (!dm_hash_insert(maps, ll->lv->name, lvm))