Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753943AbbEGKOe (ORCPT ); Thu, 7 May 2015 06:14:34 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:47955 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752660AbbEGJsw (ORCPT ); Thu, 7 May 2015 05:48:52 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Filipe Manana , Chris Mason , Luis Henriques Subject: [PATCH 3.16.y-ckt 123/180] Btrfs: fix inode eviction infinite loop after extent_same ioctl Date: Thu, 7 May 2015 10:45:32 +0100 Message-Id: <1430991989-23170-124-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> References: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1904 Lines: 54 3.16.7-ckt11 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Filipe Manana commit 113e8283869b9855c8b999796aadd506bbac155f upstream. If we pass a length of 0 to the extent_same ioctl, we end up locking an extent range with a start offset greater then its end offset (if the destination file's offset is greater than zero). This results in a warning from extent_io.c:insert_state through the following call chain: btrfs_extent_same() btrfs_double_lock() lock_extent_range() lock_extent(inode->io_tree, offset, offset + len - 1) lock_extent_bits() __set_extent_bit() insert_state() --> WARN_ON(end < start) This leads to an infinite loop when evicting the inode. This is the same problem that my previous patch titled "Btrfs: fix inode eviction infinite loop after cloning into it" addressed but for the extent_same ioctl instead of the clone ioctl. Signed-off-by: Filipe Manana Reviewed-by: Omar Sandoval Signed-off-by: Chris Mason Signed-off-by: Luis Henriques --- fs/btrfs/ioctl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 4e395f3f251d..c5b7213f267a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2941,6 +2941,9 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 len, if (src == dst) return -EINVAL; + if (len == 0) + return 0; + btrfs_double_lock(src, loff, dst, dst_loff, len); ret = extent_same_check_offsets(src, loff, len); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/