A flaw was found in the Linux kernel when attempting to "punch a hole" in files existing on an ext4 filesystem. When punching holes into a file races with the page fault of the same area, it is possible that freed blocks remain referenced from page cache pages mapped to process' address space. Thus modification of these blocks can corrupt data someone else is now storing in those blocks when at some point those pages are written to disk. Upstream fixes: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=ea3d7209ca01da209cda6f0dea8be9cc4b7a933b http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=17048e8a083fec7ad841d88ef0812707fbc7e39f http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=32ebffd3bbb4162da5ff88f9a35dd32d0a28ea70 http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=011278485ecc3cd2a3954b5d4c73101d919bf1fa References: http://seclists.org/oss-sec/2016/q2/1
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1323579]
Statement: This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 5 and 6. This issue affects the Linux kernels as shipped with Red Hat Enterprise Linux 7 and MRG-2 kernels.
kernel-4.4.7-300.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.
kernel-4.4.8-200.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2017:2077 https://access.redhat.com/errata/RHSA-2017:2077
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2017:1842 https://access.redhat.com/errata/RHSA-2017:1842
This issue has been addressed in the following products: Red Hat Enterprise MRG 2 Via RHSA-2017:2669 https://access.redhat.com/errata/RHSA-2017:2669