From cc359d180fa9c25a4c1819f17e07a422d788353d Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 15 Jun 2012 17:43:25 +0200 Subject: [PATCH] uprobes: __copy_insn() should ensure a_ops->readpage != NULL __copy_insn() blindly calls read_mapping_page(), this will crash the kernel if ->readpage == NULL, add the necessary check. For example, hugetlbfs_aops->readpage is NULL. Perhaps we should change read_mapping_page() instead. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Cc: Ananth N Mavinakayanahalli Cc: Anton Arapov Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20120615154325.GA9568@redhat.com Signed-off-by: Ingo Molnar --- kernel/events/uprobes.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f0d04530af63..604930bf9c92 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -610,6 +610,9 @@ __copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *ins if (!filp) return -EINVAL; + if (!mapping->a_ops->readpage) + return -EIO; + idx = (unsigned long)(offset >> PAGE_CACHE_SHIFT); off1 = offset &= ~PAGE_MASK; -- 2.20.1