summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorChen Gang <gang.chen@asianux.com>2013-07-03 15:02:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 16:07:31 -0700
commit9bde916bc73255dcee3d8aded990443675daa707 (patch)
tree5f8487f28ba847ff7b7ddf1df6493ba20d555ebd
parentdacbde0963d62a4962d5e8a5cc38dfd1f016124b (diff)
downloadlinux-rt-9bde916bc73255dcee3d8aded990443675daa707.tar.gz
mm/nommu.c: add additional check for vread() just like vwrite() has done
vwrite() checks for overflow. vread() should do the same thing. Since vwrite() checks the source buffer address, vread() should check the destination buffer address. Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michel Lespinasse <walken@google.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>
-rw-r--r--mm/nommu.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index 298884dcd6e7..1898b2fe9da5 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -282,6 +282,10 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
long vread(char *buf, char *addr, unsigned long count)
{
+ /* Don't allow overflow */
+ if ((unsigned long) buf + count < count)
+ count = -(unsigned long) buf;
+
memcpy(buf, addr, count);
return count;
}