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| author |   Konstantin Khlebnikov <k.khlebnikov@samsung.com> | 2013-12-05 13:30:10 +0000 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2013-12-19 17:43:09 +0000 |
| commit | 408c3658b0d49315974ce8b5aed385c8e1527595 (patch) | |
| tree | fea73a527507df8c35ba1a2c0542a61dab4349e9 | |
| parent | arm64: kconfig: select HAVE_EFFICIENT_UNALIGNED_ACCESS (diff) | |
| download | linux-dev-408c3658b0d49315974ce8b5aed385c8e1527595.tar.xz linux-dev-408c3658b0d49315974ce8b5aed385c8e1527595.zip | |
ARM64: check stack pointer in get_wchan
get_wchan() is lockless. Task may wakeup at any time and change its own stack,
thus each next stack frame may be overwritten and filled with random stuff.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/kernel/process.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index de17c89985db..0adb8f0f4549 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -308,6 +308,7 @@ struct task_struct *__switch_to(struct task_struct *prev, unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; + unsigned long stack_page; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; @@ -315,9 +316,11 @@ unsigned long get_wchan(struct task_struct *p) frame.fp = thread_saved_fp(p); frame.sp = thread_saved_sp(p); frame.pc = thread_saved_pc(p); + stack_page = (unsigned long)task_stack_page(p); do { - int ret = unwind_frame(&frame); - if (ret < 0) + if (frame.sp < stack_page || + frame.sp >= stack_page + THREAD_SIZE || + unwind_frame(&frame)) return 0; if (!in_sched_functions(frame.pc)) return frame.pc; |