[PATCH 7/9] uprobes: fix overflow in vma_address/find_active_uprobe

From: Oleg Nesterov
Date: Fri Jul 13 2012 - 12:49:16 EST


vma->vm_pgoff is "unsigned long", it should be promoted to loff_t
before the multiplication to avoid the overflow.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com>
---
kernel/events/uprobes.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 47c4e24..6194edb 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -117,7 +117,7 @@ static loff_t vma_address(struct vm_area_struct *vma, loff_t offset)
loff_t vaddr;

vaddr = vma->vm_start + offset;
- vaddr -= vma->vm_pgoff << PAGE_SHIFT;
+ vaddr -= (loff_t)vma->vm_pgoff << PAGE_SHIFT;

return vaddr;
}
@@ -1450,7 +1450,7 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)

inode = vma->vm_file->f_mapping->host;
offset = bp_vaddr - vma->vm_start;
- offset += (vma->vm_pgoff << PAGE_SHIFT);
+ offset += (loff_t)vma->vm_pgoff << PAGE_SHIFT;
uprobe = find_uprobe(inode, offset);
}

--
1.5.5.1

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