xfs: Fix integer overflow in fs/xfs/linux-2.6/xfs_ioctl*.c

The am_hreq.opcount field in the xfs_attrmulti_by_handle() interface
is not bounded correctly. The opcount is used to determine the size
of the buffer required. The size is bounded, but can overflow and so
the size checks may not be sufficient to catch invalid opcounts.
Fix it by catching opcount values that would cause overflows before
calculating the size.

Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Reviewed-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Zhitong Wang 2010-03-23 09:51:22 +11:00 коммит произвёл Alex Elder
Родитель e40152ee1e
Коммит fda168c245
2 изменённых файлов: 8 добавлений и 0 удалений

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@ -527,6 +527,10 @@ xfs_attrmulti_by_handle(
if (copy_from_user(&am_hreq, arg, sizeof(xfs_fsop_attrmulti_handlereq_t)))
return -XFS_ERROR(EFAULT);
/* overflow check */
if (am_hreq.opcount >= INT_MAX / sizeof(xfs_attr_multiop_t))
return -E2BIG;
dentry = xfs_handlereq_to_dentry(parfilp, &am_hreq.hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);

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@ -420,6 +420,10 @@ xfs_compat_attrmulti_by_handle(
sizeof(compat_xfs_fsop_attrmulti_handlereq_t)))
return -XFS_ERROR(EFAULT);
/* overflow check */
if (am_hreq.opcount >= INT_MAX / sizeof(compat_xfs_attr_multiop_t))
return -E2BIG;
dentry = xfs_compat_handlereq_to_dentry(parfilp, &am_hreq.hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);