Commit 071c529e authored by Dan Carpenter's avatar Dan Carpenter Committed by Ben Myers

xfs: underflow bug in xfs_attrlist_by_handle()

If we allocate less than sizeof(struct attrlist) then we end up
corrupting memory or doing a ZERO_PTR_SIZE dereference.

This can only be triggered with CAP_SYS_ADMIN.
Reported-by: default avatarNico Golde <nico@ngolde.de>
Reported-by: default avatarFabian Yamaguchi <fabs@goesec.de>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>
parent f2300778
...@@ -442,7 +442,8 @@ xfs_attrlist_by_handle( ...@@ -442,7 +442,8 @@ xfs_attrlist_by_handle(
return -XFS_ERROR(EPERM); return -XFS_ERROR(EPERM);
if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t))) if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t)))
return -XFS_ERROR(EFAULT); return -XFS_ERROR(EFAULT);
if (al_hreq.buflen > XATTR_LIST_MAX) if (al_hreq.buflen < sizeof(struct attrlist) ||
al_hreq.buflen > XATTR_LIST_MAX)
return -XFS_ERROR(EINVAL); return -XFS_ERROR(EINVAL);
/* /*
......
...@@ -356,7 +356,8 @@ xfs_compat_attrlist_by_handle( ...@@ -356,7 +356,8 @@ xfs_compat_attrlist_by_handle(
if (copy_from_user(&al_hreq, arg, if (copy_from_user(&al_hreq, arg,
sizeof(compat_xfs_fsop_attrlist_handlereq_t))) sizeof(compat_xfs_fsop_attrlist_handlereq_t)))
return -XFS_ERROR(EFAULT); return -XFS_ERROR(EFAULT);
if (al_hreq.buflen > XATTR_LIST_MAX) if (al_hreq.buflen < sizeof(struct attrlist) ||
al_hreq.buflen > XATTR_LIST_MAX)
return -XFS_ERROR(EINVAL); return -XFS_ERROR(EINVAL);
/* /*
......
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