Skip to main content

Browse the archive

https://github.com/torvalds/linux
29 July 2024, 15:18:00 UTC
Revision e9c6a182649f4259db704ae15a91ac820e63b0ca authored by Mikulas Patocka on 16 October 2013, 02:17:47 UTC, committed by Alasdair G Kergon on 16 October 2013, 02:17:47 UTC 
dm snapshot: fix data corruption
 
This patch fixes a particular type of data corruption that has been
encountered when loading a snapshot's metadata from disk.

When we allocate a new chunk in persistent_prepare, we increment
ps->next_free and we make sure that it doesn't point to a metadata area
by further incrementing it if necessary.

When we load metadata from disk on device activation, ps->next_free is
positioned after the last used data chunk. However, if this last used
data chunk is followed by a metadata area, ps->next_free is positioned
erroneously to the metadata area. A newly-allocated chunk is placed at
the same location as the metadata area, resulting in data or metadata
corruption.

This patch changes the code so that ps->next_free skips the metadata
area when metadata are loaded in function read_exceptions.

The patch also moves a piece of code from persistent_prepare_exception
to a separate function skip_metadata to avoid code duplication.

CVE-2013-4299

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
1 parent 61e6cfa
History
Tip revision: e9c6a182649f4259db704ae15a91ac820e63b0ca authored by Mikulas Patocka on 16 October 2013, 02:17:47 UTC
dm snapshot: fix data corruption
Tip revision: e9c6a18
File Mode Size
Documentation
arch
block
crypto
drivers
firmware
fs
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
tools
usr
virt
.gitignore -rw-r--r-- 1.1 KB
.mailmap -rw-r--r-- 4.4 KB
COPYING -rw-r--r-- 18.3 KB
CREDITS -rw-r--r-- 93.0 KB
Kbuild -rw-r--r-- 2.5 KB
Kconfig -rw-r--r-- 252 bytes
MAINTAINERS -rw-r--r-- 257.5 KB
Makefile -rw-r--r-- 47.4 KB
README -rw-r--r-- 18.3 KB
REPORTING-BUGS -rw-r--r-- 7.3 KB

README

back to top