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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Daeho Jeong <daeho.jeong@samsung.com>,
	Hobin Woo <hobin.woo@samsung.com>, Theodore Tso <tytso@mit.edu>
Subject: [PATCH 4.4 17/25] ext4: reinforce check of i_dtime when clearing high fields of uid and gid
Date: Fri, 21 Oct 2016 11:16:08 +0200	[thread overview]
Message-ID: <20161021091414.120477866@linuxfoundation.org> (raw)
In-Reply-To: <20161021091413.053290730@linuxfoundation.org>

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Daeho Jeong <daeho.jeong@samsung.com>

commit 93e3b4e6631d2a74a8cf7429138096862ff9f452 upstream.

Now, ext4_do_update_inode() clears high 16-bit fields of uid/gid
of deleted and evicted inode to fix up interoperability with old
kernels. However, it checks only i_dtime of an inode to determine
whether the inode was deleted and evicted, and this is very risky,
because i_dtime can be used for the pointer maintaining orphan inode
list, too. We need to further check whether the i_dtime is being
used for the orphan inode list even if the i_dtime is not NULL.

We found that high 16-bit fields of uid/gid of inode are unintentionally
and permanently cleared when the inode truncation is just triggered,
but not finished, and the inode metadata, whose high uid/gid bits are
cleared, is written on disk, and the sudden power-off follows that
in order.

Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Hobin Woo <hobin.woo@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/ext4/inode.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4549,14 +4549,14 @@ static int ext4_do_update_inode(handle_t
  * Fix up interoperability with old kernels. Otherwise, old inodes get
  * re-used with the upper 16 bits of the uid/gid intact
  */
-		if (!ei->i_dtime) {
+		if (ei->i_dtime && list_empty(&ei->i_orphan)) {
+			raw_inode->i_uid_high = 0;
+			raw_inode->i_gid_high = 0;
+		} else {
 			raw_inode->i_uid_high =
 				cpu_to_le16(high_16_bits(i_uid));
 			raw_inode->i_gid_high =
 				cpu_to_le16(high_16_bits(i_gid));
-		} else {
-			raw_inode->i_uid_high = 0;
-			raw_inode->i_gid_high = 0;
 		}
 	} else {
 		raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));

  parent reply	other threads:[~2016-10-21  9:45 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20161021091628uscas1p21e03f35d4481162f8066d9056c8aeb3c@uscas1p2.samsung.com>
2016-10-21  9:15 ` [PATCH 4.4 00/25] 4.4.27-stable review Greg Kroah-Hartman
2016-10-21  9:15   ` [PATCH 4.4 01/25] serial: 8250_dw: Check the data->pclk when get apb_pclk Greg Kroah-Hartman
2016-10-21  9:15   ` [PATCH 4.4 02/25] btrfs: assign error values to the correct bio structs Greg Kroah-Hartman
2016-10-21  9:15   ` [PATCH 4.4 03/25] drivers: base: dma-mapping: page align the size when unmap_kernel_range Greg Kroah-Hartman
2016-10-21  9:15   ` [PATCH 4.4 04/25] fuse: listxattr: verify xattr list Greg Kroah-Hartman
2016-10-21  9:15   ` [PATCH 4.4 06/25] fuse: fix killing s[ug]id in setattr Greg Kroah-Hartman
2016-10-21  9:15   ` [PATCH 4.4 07/25] i40e: avoid NULL pointer dereference and recursive errors on early PCI error Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 09/25] ASoC: Intel: Atom: add a missing star in a memcpy call Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 10/25] reiserfs: Unlock superblock before calling reiserfs_quota_on_mount() Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 11/25] reiserfs: switch to generic_{get,set,remove}xattr() Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 12/25] async_pq_val: fix DMA memory leak Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 13/25] scsi: arcmsr: Buffer overflow in arcmsr_iop_message_xfer() Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 14/25] scsi: arcmsr: Simplify user_len checking Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 15/25] scsi: ibmvfc: Fix I/O hang when port is not mapped Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 16/25] ext4: enforce online defrag restriction for encrypted files Greg Kroah-Hartman
2016-10-21  9:16   ` Greg Kroah-Hartman [this message]
2016-10-21  9:16   ` [PATCH 4.4 18/25] ext4: fix memory leak in ext4_insert_range() Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 19/25] ext4: allow DAX writeback for hole punch Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 20/25] ext4: release bh in make_indexed_dir Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 21/25] crypto: ghash-generic - move common definitions to a new header file Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 22/25] crypto: vmx - Fix memory corruption caused by p8_ghash Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 23/25] dlm: free workqueues after the connections Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 24/25] vfs: move permission checking into notify_change() for utimes(NULL) Greg Kroah-Hartman
2016-10-21  9:16   ` [PATCH 4.4 25/25] cfq: fix starvation of asynchronous writes Greg Kroah-Hartman
2016-10-21  9:16     ` Greg Kroah-Hartman
2016-10-21 15:44   ` [PATCH 4.4 00/25] 4.4.27-stable review Shuah Khan
2016-10-21 19:16   ` Guenter Roeck

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