6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namjae Jeon [ Upstream commit e66cf1625ec4a3fe68346119f371def713fd0a4d ] An O_CREAT open can find an existing symlink or another non-regular inode. cifs_atomic_open() calls finish_open() on it and attaches a cifsFileInfo. Symlink inodes have no CIFS release operation, so the dentry reference held by cifsFileInfo is leaked. FMODE_OPENED also prevents the VFS from following the symlink. Track whether cifs_do_create() returned an open server handle. For non-regular inodes, close the handle if present, remove the pending open, and call finish_no_open() so the VFS can continue the lookup. Do not set FMODE_CREATED unless a regular file was opened. For O_NOFOLLOW with __O_REGULAR, return -ELOOP before the VFS's -EFTYPE check. Defer closing a legacy POSIX handle on a non-regular inode until after inode lookup. This avoids closing it again if lookup fails. Fixes: d2c127197dfc ("cifs: implement i_op->atomic_open()") Signed-off-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: stable@vger.kernel.org [ replaced S_ISREG(inode->i_mode) with d_is_reg(direntry) because the older cifs_do_create() already attaches the inode. ] Signed-off-by: Sasha Levin --- fs/smb/client/dir.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/fs/smb/client/dir.c b/fs/smb/client/dir.c index 6bb0e98462a98..66bf81d159625 100644 --- a/fs/smb/client/dir.c +++ b/fs/smb/client/dir.c @@ -176,7 +176,8 @@ check_name(struct dentry *direntry, struct cifs_tcon *tcon) static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, struct tcon_link *tlink, unsigned int oflags, umode_t mode, __u32 *oplock, - struct cifs_fid *fid, struct cifs_open_info_data *buf) + struct cifs_fid *fid, struct cifs_open_info_data *buf, + bool *opened) { int rc = -ENOENT; int create_options = CREATE_NOT_DIR; @@ -191,6 +192,7 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned struct cifs_open_parms oparms; int rdwr_for_fscache = 0; + *opened = false; *oplock = 0; if (tcon->ses->server->oplocks) *oplock = REQ_OPLOCK; @@ -213,6 +215,7 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned oflags, oplock, &fid->netfid, xid); switch (rc) { case 0: + *opened = true; if (newinode == NULL) { /* query inode info */ goto cifs_create_get_file_info; @@ -229,11 +232,9 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned /* * The server may allow us to open things like * FIFOs, but the client isn't set up to deal - * with that. If it's not a regular file, just - * close it and proceed as if it were a normal - * lookup. + * with that. Keep the handle until the caller + * can finish the lookup. */ - CIFSSMBClose(xid, tcon, fid->netfid); goto cifs_create_get_file_info; } /* success, no need to query */ @@ -333,6 +334,7 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned } goto out; } + *opened = true; if (rdwr_for_fscache == 2) cifs_invalidate_cache(inode, FSCACHE_INVAL_DIO_WRITE); @@ -423,7 +425,7 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned return rc; out_err: - if (server->ops->close) + if (*opened && server->ops->close) server->ops->close(xid, tcon, fid); if (newinode) iput(newinode); @@ -442,6 +444,8 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry, struct cifs_fid fid = {}; struct cifs_pending_open open; __u32 oplock; + bool is_regular; + bool opened; struct cifsFileInfo *file_info; struct cifs_open_info_data buf = {}; @@ -501,15 +505,28 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry, cifs_add_pending_open(&fid, tlink, &open); rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, - &oplock, &fid, &buf); + &oplock, &fid, &buf, &opened); if (rc) { cifs_del_pending_open(&open); goto out; } - if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) + is_regular = d_is_reg(direntry); + if (!is_regular || !opened) { + if (opened && server->ops->close) + server->ops->close(xid, tcon, &fid); + cifs_del_pending_open(&open); + } + + if (is_regular && opened && + (oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) file->f_mode |= FMODE_CREATED; + if (!is_regular || !opened) { + rc = finish_no_open(file, NULL); + goto out; + } + rc = finish_open(file, direntry, generic_file_open); if (rc) { if (server->ops->close) @@ -564,6 +581,7 @@ int cifs_create(struct mnt_idmap *idmap, struct inode *inode, struct TCP_Server_Info *server; struct cifs_fid fid; __u32 oplock; + bool opened; struct cifs_open_info_data buf = {}; cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n", @@ -585,8 +603,9 @@ int cifs_create(struct mnt_idmap *idmap, struct inode *inode, if (server->ops->new_lease_key) server->ops->new_lease_key(&fid); - rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid, &buf); - if (!rc && server->ops->close) + rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, + &oplock, &fid, &buf, &opened); + if (!rc && opened && server->ops->close) server->ops->close(xid, tcon, &fid); cifs_free_open_info(&buf); -- 2.53.0