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| author | Grazvydas Ignotas <notasas@gmail.com> | 2015-02-12 15:00:19 -0800 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-03-12 11:10:02 +0100 |
| commit | 970970dcb4fca4fdcbb1b9bf4d7cd686796dc9d6 (patch) | |
| tree | 607f06ec3cc4dc66e56b99442aa6be0de0bc81ed | |
| parent | 5a9653fda3cf02a4bd51dae5c64b7bf94363fcae (diff) | |
| download | lwn-970970dcb4fca4fdcbb1b9bf4d7cd686796dc9d6.tar.gz lwn-970970dcb4fca4fdcbb1b9bf4d7cd686796dc9d6.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: Jiri Slaby <jslaby@suse.cz>
| -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 db2916f5f378..cf05415c25a6 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4079,7 +4079,7 @@ 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 |