mm: Fail when offset == num in first check of vm_map_pages_zero()
Subsystems (2)
PATCH 1/1 mm: Fail when offset == num in first check of vm_map_pages_zero()
If the user asks us for offset == num, we should already fail in the first check, i.e. the one testing for offsets beyond the object.
At the moment, we are failing on the second test anyway, since count cannot be 0. Still, to agree with the comment of the first test, we should first there.
--- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
mm/memory.c +1 -1
@@ -1547,7 +1547,7 @@ static int __vm_map_pages(struct vm_area_struct *vma, struct page **pages,int ret, i;/* Fail if the user requested offset is beyond the end of the object */ -if (offset > num) +if (offset >= num)return -ENXIO ;/* Fail if the user requested size exceeds available object size */
Signature · 1 line
2.17.1
Quoted 7 lines · Miguel Ojeda
If the user asks us for offset == num, we should already fail in the first check, i.e. the one testing for offsets beyond the object.
At the moment, we are failing on the second test anyway, since count cannot be 0. Still, to agree with the comment of the first test, we should first there.
I think, we need to cc linux-mm.
Quoted 22 lines
Signed-off-by Miguel Ojeda <[email protected]>--- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)mm/memory.c +1
-2@@ -1547,7 +1547,7 @@ static int __vm_map_pages(struct vm_area_struct *vma, struct page **pages,int ret, i;/* Fail if the user requested offset is beyond the end of the object */ -if (offset > num) +if (offset >= num)return -ENXIO ;/* Fail if the user requested size exceeds available object size */ --2.17.1
Quoted 4 lines · Souptick Joarder
Quoted 1 line · Miguel Ojeda
Quoted 8 lines
Quoted 6 lines
If the user asks us for offset == num, we should already fail in the first check, i.e. the one testing for offsets beyond the object.
At the moment, we are failing on the second test anyway, since count cannot be 0. Still, to agree with the comment of the first test, we should first there.
I think, we need to cc linux-mm.
Cc'ing Andrew as well as Souptick suggested me.
Cheers,
Miguel