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| author | Grazvydas Ignotas <notasas@gmail.com> | 2015-02-12 15:00:19 -0800 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-03-14 15:37:16 -0400 |
| commit | 463fb5a2cc7013f50763ee2322fa724553150842 (patch) | |
| tree | 2a74835bf0f2257b70df142ba311c55a4f14e036 | |
| parent | 42af81da88243ea738bc3b13c3120b80b6687a07 (diff) | |
| download | lwn-463fb5a2cc7013f50763ee2322fa724553150842.tar.gz lwn-463fb5a2cc7013f50763ee2322fa724553150842.zip | |
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: Sasha Levin <sasha.levin@oracle.com>
| -rw-r--r-- | mm/memory.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c index d442584fd281..4ffa7b571fb8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3558,7 +3558,7 @@ 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 |