Bug 185468
| Summary: | kernel dm: striped access beyond end of device | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 4 | Reporter: | Alasdair Kergon <agk> |
| Component: | kernel | Assignee: | Alasdair Kergon <agk> |
| Status: | CLOSED ERRATA | QA Contact: | Brian Brock <bbrock> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 4.0 | CC: | jbaron, jbrassow, mbroz |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | RHSA-2006-0575 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2006-08-10 22:44:55 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 181409 | ||
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Description
Alasdair Kergon
2006-03-14 22:57:38 UTC
From: Kevin Corry <kevcorry.com>
The dm-striped target currently does not enforce that the size of a stripe
device be a multiple of the chunk-size. Under certain conditions, this can
lead to I/O requests going off the end of an underlying device. This
test-case shows one example.
echo "0 100 linear /dev/hdb1 0" | dmsetup create linear0
echo "0 100 linear /dev/hdb1 100" | dmsetup create linear1
echo "0 200 striped 2 32 /dev/mapper/linear0 0 /dev/mapper/linear1 0" | \
dmsetup create stripe0
dd if=/dev/zero of=/dev/mapper/stripe0 bs=1k
This will produce the output:
dd: writing '/dev/mapper/stripe0': Input/output error
97+0 records in
96+0 records out
And in the kernel log will be:
attempt to access beyond end of device
dm-0: rw=0, want=104, limit=100
The patch below will check that the table size is a multiple of the stripe
chunk-size when the table is created, which will prevent the above striped
device from being created.
This should not effect tools like LVM or EVMS, since in all the cases I can
think of, striped devices are always created with the sizes being a multiple
of the chunk-size.
committed in stream u4 build 34.9. A test kernel with this patch is available from http://people.redhat.com/~jbaron/rhel4/ An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2006-0575.html |