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authorGrazvydas Ignotas <notasas@gmail.com>2015-02-12 15:00:19 -0800
committerBen Hutchings <ben@decadent.org.uk>2015-05-09 23:16:17 +0100
commitc8d452410c798d28ac96c3716b011d3d6b5d3ade (patch)
tree14c340229514d2a422e6dc5dda8da748d84563a1 /mm
parentab623fbc5a00f5525569e2c33b6b215e39a2453b (diff)
mm/memory.c: actually remap enough memory
commit 9cb12d7b4ccaa976f97ce0c5fd0f1b6a83bc2a75 upstream. For whatever reason, generic_access_phys() only remaps one page, but actually allows to access arbitrary size. It's quite easy to trigger large reads, like printing out large structure with gdb, which leads to a crash. Fix it by remapping correct size. Fixes: 28b2ee20c7cb ("access_process_vm device memory infrastructure") Signed-off-by: Grazvydas Ignotas <notasas@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 0a7bb38f4c98..452b8ba24741 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3831,7 +3831,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
if (follow_phys(vma, addr, write, &prot, &phys_addr))
return -EINVAL;
- maddr = ioremap_prot(phys_addr, PAGE_SIZE, prot);
+ maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot);
if (write)
memcpy_toio(maddr + offset, buf, len);
else