In the Linux kernel, the following vulnerability has been resolved:
ceph: supply snapshot context in ceph_zero_partial_object()
The ceph_zero_partial_object function was missing proper snapshot
context for its OSD write operations, which could lead to data
inconsistencies in snapshots.
Reproducer:
../src/vstart.sh --new -x --localhost --bluestore
./bin/ceph auth caps client.fs_a mds 'allow rwps fsname=a' mon 'allow r fsname=a' osd 'allow rw tag cephfs data=a'
mount -t ceph fs_a@.a=/ /mnt/mycephfs/ -o conf=./ceph.conf
dd if=/dev/urandom of=/mnt/mycephfs/foo bs=64K count=1
mkdir /mnt/mycephfs/.snap/snap1
md5sum /mnt/mycephfs/.snap/snap1/foo
fallocate -p -o 0 -l 4096 /mnt/mycephfs/foo
echo 3 > /proc/sys/vm/drop/caches
md5sum /mnt/mycephfs/.snap/snap1/foo # get different md5sum!!