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| author | Grazvydas Ignotas <notasas@gmail.com> | 2015-02-12 15:00:19 -0800 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-03-02 15:04:20 +0000 |
| commit | 1c64876626dd0de940279581da24c4338ebd7322 (patch) | |
| tree | 62235608010a50ab526c60832f482f32ad48d920 /mm/memory.c | |
| parent | 3ed567d6a07a0ab80cee5e60d0e775f9697779da (diff) | |
| download | lwn-1c64876626dd0de940279581da24c4338ebd7322.tar.gz lwn-1c64876626dd0de940279581da24c4338ebd7322.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: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'mm/memory.c')
| -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 769bc8906b2d..e7ae35a5ffeb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3566,7 +3566,7 @@ 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 |