Use after free vulnerability was found in percpu using previously allocated memory in bpf. First __alloc_percpu_gfp() is called, then the memory is freed with free_percpu() which triggers async pcpu_balance_work and then pcpu_extend_area_map is hitting use-after-free. CVE request (contains reproducer): http://seclists.org/oss-sec/2016/q2/332 1: percpu: fix synchronization between chunk->map_extend_work and chunk destruction ( https://www.mail-archive.com/netdev@vger.kernel.org/msg111820.html ) 2: percpu: fix synchronization between synchronous map extension and chunk destruction ( https://www.mail-archive.com/netdev@vger.kernel.org/msg111747.html )
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1335890]
Statement: This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 4, 5 and 6. This issue affects the Linux kernels as shipped with Red Hat Enterprise Linux 7 and MRG-2 and may be addressed in a future update.
Upstream patches: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4f996e234dad488e5d9ba0858bc1bae12eff82c3 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6710e594f71ccaad8101bc64321152af7cd9ea28
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2016:2574 https://rhn.redhat.com/errata/RHSA-2016-2574.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2016:2584 https://rhn.redhat.com/errata/RHSA-2016-2584.html