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authorBrian Foster <bfoster@redhat.com>2014-04-16 22:15:30 (GMT)
committerDave Chinner <david@fromorbit.com>2014-04-16 22:15:30 (GMT)
commit330033d697ed8d296fa52b5303db9d802ad901cc (patch)
treeeac219da85cd7d7f02aa5e62b1de92e42a839eb1
parent8d6c121018bf60d631c05a4a2efc468a392b97bb (diff)
downloadlinux-330033d697ed8d296fa52b5303db9d802ad901cc.tar.xz
xfs: fix tmpfile/selinux deadlock and initialize security
xfstests generic/004 reproduces an ilock deadlock using the tmpfile interface when selinux is enabled. This occurs because xfs_create_tmpfile() takes the ilock and then calls d_tmpfile(). The latter eventually calls into xfs_xattr_get() which attempts to get the lock again. E.g.: xfs_io D ffffffff81c134c0 4096 3561 3560 0x00000080 ffff8801176a1a68 0000000000000046 ffff8800b401b540 ffff8801176a1fd8 00000000001d5800 00000000001d5800 ffff8800b401b540 ffff8800b401b540 ffff8800b73a6bd0 fffffffeffffffff ffff8800b73a6bd8 ffff8800b5ddb480 Call Trace: [<ffffffff8177f969>] schedule+0x29/0x70 [<ffffffff81783a65>] rwsem_down_read_failed+0xc5/0x120 [<ffffffffa05aa97f>] ? xfs_ilock_attr_map_shared+0x1f/0x50 [xfs] [<ffffffff813b3434>] call_rwsem_down_read_failed+0x14/0x30 [<ffffffff810ed179>] ? down_read_nested+0x89/0xa0 [<ffffffffa05aa7f2>] ? xfs_ilock+0x122/0x250 [xfs] [<ffffffffa05aa7f2>] xfs_ilock+0x122/0x250 [xfs] [<ffffffffa05aa97f>] xfs_ilock_attr_map_shared+0x1f/0x50 [xfs] [<ffffffffa05701d0>] xfs_attr_get+0x90/0xe0 [xfs] [<ffffffffa0565e07>] xfs_xattr_get+0x37/0x50 [xfs] [<ffffffff8124842f>] generic_getxattr+0x4f/0x70 [<ffffffff8133fd9e>] inode_doinit_with_dentry+0x1ae/0x650 [<ffffffff81340e0c>] selinux_d_instantiate+0x1c/0x20 [<ffffffff813351bb>] security_d_instantiate+0x1b/0x30 [<ffffffff81237db0>] d_instantiate+0x50/0x70 [<ffffffff81237e85>] d_tmpfile+0xb5/0xc0 [<ffffffffa05add02>] xfs_create_tmpfile+0x362/0x410 [xfs] [<ffffffffa0559ac8>] xfs_vn_tmpfile+0x18/0x20 [xfs] [<ffffffff81230388>] path_openat+0x228/0x6a0 [<ffffffff810230f9>] ? sched_clock+0x9/0x10 [<ffffffff8105a427>] ? kvm_clock_read+0x27/0x40 [<ffffffff8124054f>] ? __alloc_fd+0xaf/0x1f0 [<ffffffff8123101a>] do_filp_open+0x3a/0x90 [<ffffffff817845e7>] ? _raw_spin_unlock+0x27/0x40 [<ffffffff8124054f>] ? __alloc_fd+0xaf/0x1f0 [<ffffffff8121e3ce>] do_sys_open+0x12e/0x210 [<ffffffff8121e4ce>] SyS_open+0x1e/0x20 [<ffffffff8178eda9>] system_call_fastpath+0x16/0x1b xfs_vn_tmpfile() also fails to initialize security on the newly created inode. Pull the d_tmpfile() call up into xfs_vn_tmpfile() after the transaction has been committed and the inode unlocked. Also, initialize security on the inode based on the parent directory provided via the tmpfile call. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
-rw-r--r--fs/xfs/xfs_inode.c5
-rw-r--r--fs/xfs/xfs_inode.h2
-rw-r--r--fs/xfs/xfs_iops.c20
3 files changed, 21 insertions, 6 deletions
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 5e7a38f..768087b 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1334,7 +1334,8 @@ int
xfs_create_tmpfile(
struct xfs_inode *dp,
struct dentry *dentry,
- umode_t mode)
+ umode_t mode,
+ struct xfs_inode **ipp)
{
struct xfs_mount *mp = dp->i_mount;
struct xfs_inode *ip = NULL;
@@ -1402,7 +1403,6 @@ xfs_create_tmpfile(
xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
ip->i_d.di_nlink--;
- d_tmpfile(dentry, VFS_I(ip));
error = xfs_iunlink(tp, ip);
if (error)
goto out_trans_abort;
@@ -1415,6 +1415,7 @@ xfs_create_tmpfile(
xfs_qm_dqrele(gdqp);
xfs_qm_dqrele(pdqp);
+ *ipp = ip;
return 0;
out_trans_abort:
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 396cc1f..f2fcde5 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -334,7 +334,7 @@ int xfs_lookup(struct xfs_inode *dp, struct xfs_name *name,
int xfs_create(struct xfs_inode *dp, struct xfs_name *name,
umode_t mode, xfs_dev_t rdev, struct xfs_inode **ipp);
int xfs_create_tmpfile(struct xfs_inode *dp, struct dentry *dentry,
- umode_t mode);
+ umode_t mode, struct xfs_inode **ipp);
int xfs_remove(struct xfs_inode *dp, struct xfs_name *name,
struct xfs_inode *ip);
int xfs_link(struct xfs_inode *tdp, struct xfs_inode *sip,
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 89b07e4..ef1ca01 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1053,11 +1053,25 @@ xfs_vn_tmpfile(
struct dentry *dentry,
umode_t mode)
{
- int error;
+ int error;
+ struct xfs_inode *ip;
+ struct inode *inode;
- error = xfs_create_tmpfile(XFS_I(dir), dentry, mode);
+ error = xfs_create_tmpfile(XFS_I(dir), dentry, mode, &ip);
+ if (unlikely(error))
+ return -error;
- return -error;
+ inode = VFS_I(ip);
+
+ error = xfs_init_security(inode, dir, &dentry->d_name);
+ if (unlikely(error)) {
+ iput(inode);
+ return -error;
+ }
+
+ d_tmpfile(dentry, inode);
+
+ return 0;
}
static const struct inode_operations xfs_inode_operations = {