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| author | Karel Zak | 2016-07-07 14:22:41 +0200 |
|---|---|---|
| committer | Karel Zak | 2016-07-07 14:22:41 +0200 |
| commit | 7164a1c34d18831ac61c6744ad14ce916d389b3f (patch) | |
| tree | 2eee6b161d0c596b9e235b980126e57941a79dd3 /libblkid/src/partitions/dos.c | |
| parent | lsns: check for OOM (diff) | |
| download | kernel-qcow2-util-linux-7164a1c34d18831ac61c6744ad14ce916d389b3f.tar.gz kernel-qcow2-util-linux-7164a1c34d18831ac61c6744ad14ce916d389b3f.tar.xz kernel-qcow2-util-linux-7164a1c34d18831ac61c6744ad14ce916d389b3f.zip | |
libblkid: ignore extended partition at zero offset
If the extended partition starts at zero LBA then MBR is interpreted
as EBR and all is recursively parsed... result is out-of-memory.
MBR --extended-partition--> EBR --> MBR --> ENB --> MBR ...
Note that such PT is not possible to create by standard partitioning
tools.
Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1349536
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'libblkid/src/partitions/dos.c')
| -rw-r--r-- | libblkid/src/partitions/dos.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/libblkid/src/partitions/dos.c b/libblkid/src/partitions/dos.c index 9bba32f3b..e79f124f8 100644 --- a/libblkid/src/partitions/dos.c +++ b/libblkid/src/partitions/dos.c @@ -47,6 +47,12 @@ static int parse_dos_extended(blkid_probe pr, blkid_parttable tab, int ct_nodata = 0; /* count ext.partitions without data partitions */ int i; + DBG(LOWPROBE, ul_debug("parse EBR [start=%d, size=%d]", ex_start/ssf, ex_size/ssf)); + if (ex_start == 0) { + DBG(LOWPROBE, ul_debug("Bad offset in primary extended partition -- ignore")); + return 0; + } + while (1) { struct dos_partition *p, *p0; uint32_t start, size; @@ -116,8 +122,12 @@ static int parse_dos_extended(blkid_probe pr, blkid_parttable tab, start = dos_partition_get_start(p) * ssf; size = dos_partition_get_size(p) * ssf; - if (size && is_extended(p)) - break; + if (size && is_extended(p)) { + if (start == 0) + DBG(LOWPROBE, ul_debug("#%d: EBR link offset is zero -- ignore", i + 1)); + else + break; + } } if (i == 4) goto leave; |