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| author | David Rientjes <rientjes@google.com> | 2008-10-13 19:42:12 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-10-22 14:13:25 -0700 |
| commit | 76d8cb9a1e102231935e586e888b10ea6ca41101 (patch) | |
| tree | 75830117127e8712b839cbf0a7cceb740b517e99 | |
| parent | 7a69c701bd95e1dc0eaf7e4008e5fd409ac7e042 (diff) | |
| download | lwn-76d8cb9a1e102231935e586e888b10ea6ca41101.tar.gz lwn-76d8cb9a1e102231935e586e888b10ea6ca41101.zip | |
x86: avoid dereferencing beyond stack + THREAD_SIZE
commit 60e6258cd43f9b06884f04f0f7cefb9c40f17a32 upstream
It's possible for get_wchan() to dereference past task->stack + THREAD_SIZE
while iterating through instruction pointers if fp equals the upper boundary,
causing a kernel panic.
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/x86/kernel/process_64.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index c6eb5c91e5f6..a803de31600e 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -740,12 +740,12 @@ unsigned long get_wchan(struct task_struct *p) if (!p || p == current || p->state==TASK_RUNNING) return 0; stack = (unsigned long)task_stack_page(p); - if (p->thread.sp < stack || p->thread.sp > stack+THREAD_SIZE) + if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE) return 0; fp = *(u64 *)(p->thread.sp); do { if (fp < (unsigned long)stack || - fp > (unsigned long)stack+THREAD_SIZE) + fp >= (unsigned long)stack+THREAD_SIZE) return 0; ip = *(u64 *)(fp+8); if (!in_sched_functions(ip)) |