From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>,
Theodore Tso <tytso@mit.edu>, Eric Biggers <ebiggers@google.com>
Subject: [PATCH 4.4 17/20] ext4 crypto: use dget_parent() in ext4_d_revalidate()
Date: Fri, 5 May 2017 11:33:07 -0700 [thread overview]
Message-ID: <20170505183231.608205479@linuxfoundation.org> (raw)
In-Reply-To: <20170505183230.937615081@linuxfoundation.org>
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Theodore Ts'o <tytso@mit.edu>
commit 3d43bcfef5f0548845a425365011c499875491b0 upstream.
This avoids potential problems caused by a race where the inode gets
renamed out from its parent directory and the parent directory is
deleted while ext4_d_revalidate() is running.
Fixes: 28b4c263961c
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ext4/crypto.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -477,16 +477,21 @@ uint32_t ext4_validate_encryption_key_si
*/
static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags)
{
- struct inode *dir = d_inode(dentry->d_parent);
- struct ext4_crypt_info *ci = EXT4_I(dir)->i_crypt_info;
+ struct dentry *dir;
+ struct ext4_crypt_info *ci;
int dir_has_key, cached_with_key;
- if (!ext4_encrypted_inode(dir))
+ dir = dget_parent(dentry);
+ if (!ext4_encrypted_inode(d_inode(dir))) {
+ dput(dir);
return 0;
+ }
+ ci = EXT4_I(d_inode(dir))->i_crypt_info;
/* this should eventually be an flag in d_flags */
cached_with_key = dentry->d_fsdata != NULL;
dir_has_key = (ci != NULL);
+ dput(dir);
/*
* If the dentry was cached without the key, and it is a
next prev parent reply other threads:[~2017-05-05 18:36 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-05 18:32 [PATCH 4.4 00/20] 4.4.67-stable review Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 01/20] timerfd: Protect the might cancel mechanism proper Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 02/20] Handle mismatched open calls Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 03/20] ASoC: intel: Fix PM and non-atomic crash in bytcr drivers Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 04/20] ALSA: ppc/awacs: shut up maybe-uninitialized warning Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 05/20] drbd: avoid redefinition of BITS_PER_PAGE Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 06/20] mtd: avoid stack overflow in MTD CFI code Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 07/20] net: tg3: avoid uninitialized variable warning Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 08/20] scsi: cxlflash: Scan host only after the port is ready for I/O Greg Kroah-Hartman
2017-05-05 18:32 ` [PATCH 4.4 09/20] scsi: cxlflash: Fix to avoid EEH and host reset collisions Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 10/20] scsi: cxlflash: Improve EEH recovery time Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 11/20] 8250_pci: Fix potential use-after-free in error path Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 12/20] netlink: Allow direct reclaim for fallback allocation Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 13/20] IB/qib: rename BITS_PER_PAGE to RVT_BITS_PER_PAGE Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 14/20] IB/ehca: fix maybe-uninitialized warnings Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 15/20] ext4: require encryption feature for EXT4_IOC_SET_ENCRYPTION_POLICY Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 16/20] ext4 crypto: revalidate dentry after adding or removing the key Greg Kroah-Hartman
2017-05-05 18:33 ` Greg Kroah-Hartman [this message]
2017-05-05 18:33 ` [PATCH 4.4 18/20] ext4/fscrypto: avoid RCU lookup in d_revalidate Greg Kroah-Hartman
2017-05-05 18:33 ` [PATCH 4.4 19/20] nfsd4: minor NFSv2/v3 write decoding cleanup Greg Kroah-Hartman
2017-05-06 1:58 ` [PATCH 4.4 00/20] 4.4.67-stable review Shuah Khan
2017-05-06 3:41 ` Greg Kroah-Hartman
2017-05-07 20:53 ` Guenter Roeck
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