| Date | Fri, 15 Jun 2012 17:43:25 +0200 | From | Oleg Nesterov <> | Subject | [PATCH 02/15] uprobes: __copy_insn() should ensure a_ops->readpage != NULL |
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__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 <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- kernel/events/uprobes.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f0d0453..604930b 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; -- 1.5.5.1
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