From: Jeff Moyer <[email protected]> commit 75e1c70fc31490ef8a373ea2a4bea2524099b478 upstream.
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 <[email protected]> Signed-off-by: Jeff Moyer <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- fs/aio.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index 48fdeeb..94b6cd6 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; -- 1.7.3.3 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
