From 5f21c96dd5c615341963036ae8f5e4f5227a818d Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 26 Jul 2011 11:30:29 -0700 Subject: [PATCH] ceph: protect access to d_parent d_parent is protected by d_lock: use it when looking up a dentry's parent directory inode. Also take a reference and drop it in the caller to avoid a use-after-free. Reported-by: Al Viro Reviewed-by: Yehuda Sadeh Signed-off-by: Sage Weil --- fs/ceph/dir.c | 15 +++++++++++++++ fs/ceph/file.c | 8 +++++--- fs/ceph/inode.c | 4 +++- fs/ceph/ioctl.c | 4 +++- fs/ceph/super.h | 9 +-------- fs/ceph/xattr.c | 8 ++++++-- 6 files changed, 33 insertions(+), 15 deletions(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 883c9546111d..ed296ec121d1 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -71,6 +71,21 @@ out_unlock: return 0; } +struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry) +{ + struct inode *inode = NULL; + + if (!dentry) + return NULL; + + spin_lock(&dentry->d_lock); + if (dentry->d_parent) { + inode = dentry->d_parent->d_inode; + ihold(inode); + } + spin_unlock(&dentry->d_lock); + return inode; +} /* diff --git a/fs/ceph/file.c b/fs/ceph/file.c index f34d47d66e7c..45fbd69daabe 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -122,7 +122,7 @@ int ceph_open(struct inode *inode, struct file *file) struct ceph_mds_client *mdsc = fsc->mdsc; struct ceph_mds_request *req; struct ceph_file_info *cf = file->private_data; - struct inode *parent_inode = file->f_dentry->d_parent->d_inode; + struct inode *parent_inode = NULL; int err; int flags, fmode, wanted; @@ -194,8 +194,10 @@ int ceph_open(struct inode *inode, struct file *file) req->r_inode = inode; ihold(inode); req->r_num_caps = 1; - err = ceph_mdsc_do_request(mdsc, (flags & (O_CREAT|O_TRUNC)) ? - parent_inode : NULL, req); + if (flags & (O_CREAT|O_TRUNC)) + parent_inode = ceph_get_dentry_parent_inode(file->f_dentry); + err = ceph_mdsc_do_request(mdsc, parent_inode, req); + iput(parent_inode); if (!err) err = ceph_init_file(inode, file, req->r_fmode); ceph_mdsc_put_request(req); diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 2717dc4e443c..a7db56f1523b 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1562,7 +1562,7 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; struct ceph_inode_info *ci = ceph_inode(inode); - struct inode *parent_inode = dentry->d_parent->d_inode; + struct inode *parent_inode; const unsigned int ia_valid = attr->ia_valid; struct ceph_mds_request *req; struct ceph_mds_client *mdsc = ceph_sb_to_client(dentry->d_sb)->mdsc; @@ -1745,7 +1745,9 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) req->r_inode_drop = release; req->r_args.setattr.mask = cpu_to_le32(mask); req->r_num_caps = 1; + parent_inode = ceph_get_dentry_parent_inode(dentry); err = ceph_mdsc_do_request(mdsc, parent_inode, req); + iput(parent_inode); } dout("setattr %p result=%d (%s locally, %d remote)\n", inode, err, ceph_cap_string(dirtied), mask); diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c index a757a5680578..3b256b50f7d8 100644 --- a/fs/ceph/ioctl.c +++ b/fs/ceph/ioctl.c @@ -38,7 +38,7 @@ static long ceph_ioctl_get_layout(struct file *file, void __user *arg) static long ceph_ioctl_set_layout(struct file *file, void __user *arg) { struct inode *inode = file->f_dentry->d_inode; - struct inode *parent_inode = file->f_dentry->d_parent->d_inode; + struct inode *parent_inode; struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc; struct ceph_mds_request *req; struct ceph_ioctl_layout l; @@ -87,7 +87,9 @@ static long ceph_ioctl_set_layout(struct file *file, void __user *arg) req->r_args.setlayout.layout.fl_pg_preferred = cpu_to_le32(l.preferred_osd); + parent_inode = ceph_get_dentry_parent_inode(file->f_dentry); err = ceph_mdsc_do_request(mdsc, parent_inode, req); + iput(parent_inode); ceph_mdsc_put_request(req); return err; } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index c24891a5bec2..c1eb9a014b74 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -801,6 +801,7 @@ extern void ceph_dentry_lru_touch(struct dentry *dn); extern void ceph_dentry_lru_del(struct dentry *dn); extern void ceph_invalidate_dentry_lease(struct dentry *dentry); extern unsigned ceph_dentry_hash(struct dentry *dn); +extern struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry); /* * our d_ops vary depending on whether the inode is live, @@ -823,14 +824,6 @@ extern int ceph_encode_locks(struct inode *i, struct ceph_pagelist *p, int p_locks, int f_locks); extern int lock_to_ceph_filelock(struct file_lock *fl, struct ceph_filelock *c); -static inline struct inode *get_dentry_parent_inode(struct dentry *dentry) -{ - if (dentry && dentry->d_parent) - return dentry->d_parent->d_inode; - - return NULL; -} - /* debugfs.c */ extern int ceph_fs_debugfs_init(struct ceph_fs_client *client); extern void ceph_fs_debugfs_cleanup(struct ceph_fs_client *client); diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c index f42d730f1b66..96c6739a0280 100644 --- a/fs/ceph/xattr.c +++ b/fs/ceph/xattr.c @@ -629,7 +629,7 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name, struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb); struct inode *inode = dentry->d_inode; struct ceph_inode_info *ci = ceph_inode(inode); - struct inode *parent_inode = dentry->d_parent->d_inode; + struct inode *parent_inode; struct ceph_mds_request *req; struct ceph_mds_client *mdsc = fsc->mdsc; int err; @@ -677,7 +677,9 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name, req->r_data_len = size; dout("xattr.ver (before): %lld\n", ci->i_xattrs.version); + parent_inode = ceph_get_dentry_parent_inode(dentry); err = ceph_mdsc_do_request(mdsc, parent_inode, req); + iput(parent_inode); ceph_mdsc_put_request(req); dout("xattr.ver (after): %lld\n", ci->i_xattrs.version); @@ -788,7 +790,7 @@ static int ceph_send_removexattr(struct dentry *dentry, const char *name) struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb); struct ceph_mds_client *mdsc = fsc->mdsc; struct inode *inode = dentry->d_inode; - struct inode *parent_inode = dentry->d_parent->d_inode; + struct inode *parent_inode; struct ceph_mds_request *req; int err; @@ -802,7 +804,9 @@ static int ceph_send_removexattr(struct dentry *dentry, const char *name) req->r_num_caps = 1; req->r_path2 = kstrdup(name, GFP_NOFS); + parent_inode = ceph_get_dentry_parent_inode(dentry); err = ceph_mdsc_do_request(mdsc, parent_inode, req); + iput(parent_inode); ceph_mdsc_put_request(req); return err; } -- 2.20.1