[PATCH v2 0/3] sched: Always check the integrity of the canary

From: Aaron Tomlin
Date: Tue Sep 09 2014 - 05:46:03 EST


Resending with "v2" added to each subject line:


Currently in the event of a stack overrun a call to schedule()
does not check for this type of corruption. This corruption is
often silent and can go unnoticed. However once the corrupted
region is examined at a later stage, the outcome is undefined
and often results in a sporadic page fault which cannot be
handled.

The first patch adds a canary to init_task's end of stack.
While the second patch provides a helper to determine the
integrity of the canary. The third checks for a stack
overrun and takes appropriate action since the damage
is already done, there is no point in continuing.

Changes since v1:

* Rebased against v3.17-rc4
* Add a canary to init_task - Oleg Nesterov
* Fix various code formatting issues - Peter Zijlstra
* Introduce Kconfig option - Peter Zijlstra

Aaron Tomlin (3):
init/main.c: Give init_task a canary
sched: Add helper for task stack page overrun checking
sched: BUG when stack end location is over written

arch/powerpc/mm/fault.c | 5 +----
arch/x86/mm/fault.c | 5 +----
include/linux/sched.h | 4 ++++
init/main.c | 1 +
kernel/fork.c | 12 +++++++++---
kernel/sched/core.c | 4 ++++
kernel/trace/trace_stack.c | 4 +---
lib/Kconfig.debug | 12 ++++++++++++
8 files changed, 33 insertions(+), 14 deletions(-)

--
1.9.3

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