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From: wzt.wzt on 16 Mar 2010 23:30 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(a)alibaba-inc.com> --- fs/xfs/linux-2.6/xfs_ioctl.c | 4 ++++ fs/xfs/linux-2.6/xfs_ioctl32.c | 4 ++++ 2 files changed, 8 insertions(+), 0 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c index a034cf6..b716ec8 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl.c +++ b/fs/xfs/linux-2.6/xfs_ioctl.c @@ -526,6 +526,10 @@ 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); diff --git a/fs/xfs/linux-2.6/xfs_ioctl32.c b/fs/xfs/linux-2.6/xfs_ioctl32.c index be1527b..c9d9d5e 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl32.c +++ b/fs/xfs/linux-2.6/xfs_ioctl32.c @@ -419,6 +419,10 @@ 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); -- 1.6.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |