[PATCH 00/15] v3 kernel core pieces refcount conversions

Elena Reshetova
2017-07-17T10:43:11Z

Changes in v3:
* SoB chain corrected
* minor corrections based on v2 feedback
* rebase on linux-next/master as of today

Changes in v2:
* dropped already merged patches
* rebase on top of linux-next/master
* Now by default refcount_t = atomic_t (*) and uses all atomic
standard operations unless CONFIG_REFCOUNT_FULL is enabled.
This is a compromise for the systems that are critical on
performance (such as net) and cannot accept even slight delay
on the refcounter operations.

This series, for core kernel components, replaces atomic_t reference
counters with the new refcount_t type and API (see include/linux/refcount.h).
By doing this we prevent intentional or accidental
underflows or overflows that can led to use-after-free vulnerabilities.

The patches are fully independent and can be cherry-picked separately.
If there are no objections to the patches, please merge them via respective trees.

If you want to test with refcount_t protection enabled, CONFIG_REFCOUNT_FULL
must be enabled.

* The respective change is currently merged into -next as
"locking/refcount: Create unchecked atomic_t implementation".

Elena Reshetova (15):
kernel: convert sighand_struct.count from atomic_t to refcount_t
kernel: convert signal_struct.sigcnt from atomic_t to refcount_t
kernel: convert user_struct.__count from atomic_t to refcount_t
kernel: convert task_struct.usage from atomic_t to refcount_t
kernel: convert task_struct.stack_refcount from atomic_t to refcount_t
kernel: convert perf_event_context.refcount from atomic_t to
refcount_t
kernel: convert ring_buffer.refcount from atomic_t to refcount_t
kernel: convert ring_buffer.aux_refcount from atomic_t to refcount_t
kernel: convert uprobe.ref from atomic_t to refcount_t
kernel: convert nsproxy.count from atomic_t to refcount_t
kernel: convert group_info.usage from atomic_t to refcount_t
kernel: convert cred.usage from atomic_t to refcount_t
sched: convert numa_group.refcount from atomic_t to refcount_t
kernel: convert futex_pi_state.refcount from atomic_t to refcount_t
kernel: convert kcov.refcount from atomic_t to refcount_t

fs/exec.c | 4 ++--
fs/proc/task_nommu.c | 2 +-
include/linux/cred.h | 13 ++++++------
include/linux/init_task.h | 7 +++---
include/linux/nsproxy.h | 6 +++---
include/linux/perf_event.h | 3 ++-
include/linux/sched.h | 5 +++--
include/linux/sched/signal.h | 5 +++--
include/linux/sched/task.h | 4 ++--
include/linux/sched/task_stack.h | 2 +-
include/linux/sched/user.h | 5 +++--
kernel/cred.c | 46 ++++++++++++++++++++--------------------
kernel/events/core.c | 18 ++++++++--------
kernel/events/internal.h | 5 +++--
kernel/events/ring_buffer.c | 8 +++----
kernel/events/uprobes.c | 8 +++----
kernel/fork.c | 24 ++++++++++-----------
kernel/futex.c | 13 ++++++------
kernel/groups.c | 2 +-
kernel/kcov.c | 9 ++++----
kernel/nsproxy.c | 6 +++---
kernel/sched/fair.c | 8 +++----
kernel/user.c | 8 +++----
23 files changed, 110 insertions(+), 101 deletions(-)

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2.7.4