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authorGrazvydas Ignotas <notasas@gmail.com>2015-02-12 15:00:19 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-18 14:10:54 +0100
commit6f5468a717c8f18e721dc9bc7f8d7ce41f22eb1a (patch)
treedaf5fc3b1aefc9fbb09c34b28f4f8df0cc8fce1e /mm
parentcf4a79699bbeb8d677aa5f3a145a066ead7b43c4 (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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 2c3536cc6c63..6aa7822bb64d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3561,7 +3561,7 @@ 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