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authorJeff Moyer <jmoyer@redhat.com>2010-09-10 14:16:00 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2011-03-21 12:45:40 -0700
commit8228803d07f7f154e97a71475ccd547afeea86bf (patch)
tree6f7d125cd676bd4c2b4ded979522feb48c4b8632 /fs
parentca4711e759f048f03ac3118bce3f82df3cf664ac (diff)
aio: check for multiplication overflow in do_io_submit
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 <taviso@cmpxchg8b.com> Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/aio.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 1cf12b3dd83a..4e58cd482a02 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1660,6 +1660,9 @@ SYSCALL_DEFINE3(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;