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| author | David Rientjes <rientjes@google.com> | 2008-10-07 14:15:11 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-12 11:18:59 +0200 |
| commit | e1e23bb0513520035ec934fa3483507cb6648b7c (patch) | |
| tree | a05f96cf556599a3a0dbc0de852c57921ae6051f /arch/x86/kernel/process_64.c | |
| parent | fd048088306656824958e7783ffcee27e241b361 (diff) | |
| download | lwn-e1e23bb0513520035ec934fa3483507cb6648b7c.tar.gz lwn-e1e23bb0513520035ec934fa3483507cb6648b7c.zip | |
x86: avoid dereferencing beyond stack + THREAD_SIZE
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>
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -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 2a8ccb9238b4..b6b508ea7110 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -754,12 +754,12 @@ 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)) |