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authorJeff Moyer <jmoyer@redhat.com>2010-09-10 14:16:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-09-14 17:02:37 -0700
commit75e1c70fc31490ef8a373ea2a4bea2524099b478 (patch)
tree4fc943276b4a34374ac26d69e63b815bf66c2451 /fs/aio.c
parentbfa88ea7ee9e6b4fd673e45a8cc0a8e0b7ef4761 (diff)
downloadlinux-stericsson-75e1c70fc31490ef8a373ea2a4bea2524099b478.tar.gz
aio: check for multiplication overflow in do_io_submit
Tavis Ormandy pointed out that do_io_submit does not do proper bounds checking on the passed-in iocb array:        if (unlikely(nr < 0))                return -EINVAL;        if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(iocbpp)))))                return -EFAULT;                      ^^^^^^^^^^^^^^^^^^ The attached patch checks for overflow, and if it is detected, the number of iocbs submitted is scaled down to a number that will fit in the long.  This is an ok thing to do, as sys_io_submit is documented as returning the number of iocbs submitted, so callers should handle a return value of less than the 'nr' argument passed in. Reported-by: Tavis Ormandy <taviso@cmpxchg8b.com> Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/aio.c')
-rw-r--r--fs/aio.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 3006b5bc33d6..1320b2a05fb2 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1659,6 +1659,9 @@ long do_io_submit(aio_context_t ctx_id, long nr,
if (unlikely(nr < 0))
return -EINVAL;
+ if (unlikely(nr > LONG_MAX/sizeof(*iocbpp)))
+ nr = LONG_MAX/sizeof(*iocbpp);
+
if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(*iocbpp)))))
return -EFAULT;