From patchwork Mon Jan 24 13:43:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Hutchings X-Patchwork-Id: 536472 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C743AC433F5 for ; Mon, 24 Jan 2022 13:55:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235583AbiAXNzU (ORCPT ); Mon, 24 Jan 2022 08:55:20 -0500 Received: from maynard.decadent.org.uk ([95.217.213.242]:41962 "EHLO maynard.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234941AbiAXNzT (ORCPT ); Mon, 24 Jan 2022 08:55:19 -0500 Received: from 168.7-181-91.adsl-dyn.isp.belgacom.be ([91.181.7.168] helo=deadeye) by maynard with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nBzcu-0004zk-3s; Mon, 24 Jan 2022 14:43:20 +0100 Received: from ben by deadeye with local (Exim 4.95) (envelope-from ) id 1nBzct-009hpT-Kj; Mon, 24 Jan 2022 14:43:19 +0100 Date: Mon, 24 Jan 2022 14:43:19 +0100 From: Ben Hutchings To: stable@vger.kernel.org Cc: Miklos Szeredi , Jan Kara Subject: [PATCH 4.9 1/2] fuse: fix bad inode Message-ID: MIME-Version: 1.0 Content-Disposition: inline X-SA-Exim-Connect-IP: 91.181.7.168 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on maynard); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Miklos Szeredi commit 5d069dbe8aaf2a197142558b6fb2978189ba3454 upstream. Jan Kara's analysis of the syzbot report (edited): The reproducer opens a directory on FUSE filesystem, it then attaches dnotify mark to the open directory. After that a fuse_do_getattr() call finds that attributes returned by the server are inconsistent, and calls make_bad_inode() which, among other things does: inode->i_mode = S_IFREG; This then confuses dnotify which doesn't tear down its structures properly and eventually crashes. Avoid calling make_bad_inode() on a live inode: switch to a private flag on the fuse inode. Also add the test to ops which the bad_inode_ops would have caught. This bug goes back to the initial merge of fuse in 2.6.14... Reported-by: syzbot+f427adf9324b92652ccc@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi Tested-by: Jan Kara Cc: [bwh: Backported to 4.9: - Drop changes in fuse_dir_fsync(), fuse_readahead(), fuse_evict_inode() - In fuse_get_link(), return ERR_PTR(-EIO) for bad inodes - Convert some additional calls to is_bad_inode() - Adjust filename, context] Signed-off-by: Ben Hutchings --- fs/fuse/acl.c | 6 ++++++ fs/fuse/dir.c | 40 +++++++++++++++++++++++++++++++++++----- fs/fuse/file.c | 27 ++++++++++++++++++--------- fs/fuse/fuse_i.h | 12 ++++++++++++ fs/fuse/inode.c | 2 +- fs/fuse/xattr.c | 9 +++++++++ 6 files changed, 81 insertions(+), 15 deletions(-) diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c index ec85765502f1..990529da5354 100644 --- a/fs/fuse/acl.c +++ b/fs/fuse/acl.c @@ -19,6 +19,9 @@ struct posix_acl *fuse_get_acl(struct inode *inode, int type) void *value = NULL; struct posix_acl *acl; + if (fuse_is_bad(inode)) + return ERR_PTR(-EIO); + if (!fc->posix_acl || fc->no_getxattr) return NULL; @@ -53,6 +56,9 @@ int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type) const char *name; int ret; + if (fuse_is_bad(inode)) + return -EIO; + if (!fc->posix_acl || fc->no_setxattr) return -EOPNOTSUPP; diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index b41cc537eb31..c40bdfab0a85 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -187,7 +187,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags) int ret; inode = d_inode_rcu(entry); - if (inode && is_bad_inode(inode)) + if (inode && fuse_is_bad(inode)) goto invalid; else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) || (flags & LOOKUP_REVAL)) { @@ -364,6 +364,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, bool outarg_valid = true; bool locked; + if (fuse_is_bad(dir)) + return ERR_PTR(-EIO); + locked = fuse_lock_inode(dir); err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, &outarg, &inode); @@ -504,6 +507,9 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry, struct fuse_conn *fc = get_fuse_conn(dir); struct dentry *res = NULL; + if (fuse_is_bad(dir)) + return -EIO; + if (d_in_lookup(entry)) { res = fuse_lookup(dir, entry, 0); if (IS_ERR(res)) @@ -551,6 +557,9 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args, int err; struct fuse_forget_link *forget; + if (fuse_is_bad(dir)) + return -EIO; + forget = fuse_alloc_forget(); if (!forget) return -ENOMEM; @@ -672,6 +681,9 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry) struct fuse_conn *fc = get_fuse_conn(dir); FUSE_ARGS(args); + if (fuse_is_bad(dir)) + return -EIO; + args.in.h.opcode = FUSE_UNLINK; args.in.h.nodeid = get_node_id(dir); args.in.numargs = 1; @@ -708,6 +720,9 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry) struct fuse_conn *fc = get_fuse_conn(dir); FUSE_ARGS(args); + if (fuse_is_bad(dir)) + return -EIO; + args.in.h.opcode = FUSE_RMDIR; args.in.h.nodeid = get_node_id(dir); args.in.numargs = 1; @@ -786,6 +801,9 @@ static int fuse_rename2(struct inode *olddir, struct dentry *oldent, struct fuse_conn *fc = get_fuse_conn(olddir); int err; + if (fuse_is_bad(olddir)) + return -EIO; + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) return -EINVAL; @@ -921,7 +939,7 @@ static int fuse_do_getattr(struct inode *inode, struct kstat *stat, if (!err) { if (fuse_invalid_attr(&outarg.attr) || (inode->i_mode ^ outarg.attr.mode) & S_IFMT) { - make_bad_inode(inode); + fuse_make_bad(inode); err = -EIO; } else { fuse_change_attributes(inode, &outarg.attr, @@ -1114,6 +1132,9 @@ static int fuse_permission(struct inode *inode, int mask) bool refreshed = false; int err = 0; + if (fuse_is_bad(inode)) + return -EIO; + if (!fuse_allow_current_process(fc)) return -EACCES; @@ -1251,7 +1272,7 @@ static int fuse_direntplus_link(struct file *file, dput(dentry); goto retry; } - if (is_bad_inode(inode)) { + if (fuse_is_bad(inode)) { dput(dentry); return -EIO; } @@ -1349,7 +1370,7 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx) u64 attr_version = 0; bool locked; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) return -EIO; req = fuse_get_req(fc, 1); @@ -1409,6 +1430,9 @@ static const char *fuse_get_link(struct dentry *dentry, if (!dentry) return ERR_PTR(-ECHILD); + if (fuse_is_bad(inode)) + return ERR_PTR(-EIO); + link = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!link) return ERR_PTR(-ENOMEM); @@ -1707,7 +1731,7 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, if (fuse_invalid_attr(&outarg.attr) || (inode->i_mode ^ outarg.attr.mode) & S_IFMT) { - make_bad_inode(inode); + fuse_make_bad(inode); err = -EIO; goto error; } @@ -1763,6 +1787,9 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr) struct file *file = (attr->ia_valid & ATTR_FILE) ? attr->ia_file : NULL; int ret; + if (fuse_is_bad(inode)) + return -EIO; + if (!fuse_allow_current_process(get_fuse_conn(inode))) return -EACCES; @@ -1821,6 +1848,9 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, struct inode *inode = d_inode(entry); struct fuse_conn *fc = get_fuse_conn(inode); + if (fuse_is_bad(inode)) + return -EIO; + if (!fuse_allow_current_process(fc)) return -EACCES; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index cea2317e0138..8aef8e56eb1b 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -206,6 +206,9 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir) fc->atomic_o_trunc && fc->writeback_cache; + if (fuse_is_bad(inode)) + return -EIO; + err = generic_file_open(inode, file); if (err) return err; @@ -411,7 +414,7 @@ static int fuse_flush(struct file *file, fl_owner_t id) struct fuse_flush_in inarg; int err; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) return -EIO; if (fc->no_flush) @@ -459,7 +462,7 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end, struct fuse_fsync_in inarg; int err; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) return -EIO; inode_lock(inode); @@ -771,7 +774,7 @@ static int fuse_readpage(struct file *file, struct page *page) int err; err = -EIO; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) goto out; err = fuse_do_readpage(file, page); @@ -898,7 +901,7 @@ static int fuse_readpages(struct file *file, struct address_space *mapping, int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ); err = -EIO; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) goto out; data.file = file; @@ -928,6 +931,9 @@ static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to) struct inode *inode = iocb->ki_filp->f_mapping->host; struct fuse_conn *fc = get_fuse_conn(inode); + if (fuse_is_bad(inode)) + return -EIO; + /* * In auto invalidate mode, always update attributes on read. * Otherwise, only update if we attempt to read past EOF (to ensure @@ -1123,7 +1129,7 @@ static ssize_t fuse_perform_write(struct file *file, int err = 0; ssize_t res = 0; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) return -EIO; if (inode->i_size < pos + iov_iter_count(ii)) @@ -1180,6 +1186,9 @@ static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from) ssize_t err; loff_t endbyte = 0; + if (fuse_is_bad(inode)) + return -EIO; + if (get_fuse_conn(inode)->writeback_cache) { /* Update size (EOF optimization) and mode (SUID clearing) */ err = fuse_update_attributes(mapping->host, NULL, file, NULL); @@ -1415,7 +1424,7 @@ static ssize_t __fuse_direct_read(struct fuse_io_priv *io, struct file *file = io->file; struct inode *inode = file_inode(file); - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) return -EIO; res = fuse_direct_io(io, iter, ppos, 0); @@ -1438,7 +1447,7 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from) struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file); ssize_t res; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) return -EIO; /* Don't allow parallel writes to the same file */ @@ -1911,7 +1920,7 @@ static int fuse_writepages(struct address_space *mapping, int err; err = -EIO; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) goto out; data.inode = inode; @@ -2687,7 +2696,7 @@ long fuse_ioctl_common(struct file *file, unsigned int cmd, if (!fuse_allow_current_process(fc)) return -EACCES; - if (is_bad_inode(inode)) + if (fuse_is_bad(inode)) return -EIO; return fuse_do_ioctl(file, cmd, arg, flags); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index f84dd6d87d90..bd82c09b053d 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -115,6 +115,8 @@ enum { FUSE_I_INIT_RDPLUS, /** An operation changing file size is in progress */ FUSE_I_SIZE_UNSTABLE, + /* Bad inode */ + FUSE_I_BAD, }; struct fuse_conn; @@ -688,6 +690,16 @@ static inline u64 get_node_id(struct inode *inode) return get_fuse_inode(inode)->nodeid; } +static inline void fuse_make_bad(struct inode *inode) +{ + set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state); +} + +static inline bool fuse_is_bad(struct inode *inode) +{ + return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state)); +} + /** Device operations */ extern const struct file_operations fuse_dev_operations; diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 7a9b1069d267..77b8f0f26407 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -316,7 +316,7 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid, unlock_new_inode(inode); } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { /* Inode has changed type, any I/O on the old should fail */ - make_bad_inode(inode); + fuse_make_bad(inode); iput(inode); goto retry; } diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c index 3caac46b08b0..134bbc432ae6 100644 --- a/fs/fuse/xattr.c +++ b/fs/fuse/xattr.c @@ -113,6 +113,9 @@ ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) struct fuse_getxattr_out outarg; ssize_t ret; + if (fuse_is_bad(inode)) + return -EIO; + if (!fuse_allow_current_process(fc)) return -EACCES; @@ -178,6 +181,9 @@ static int fuse_xattr_get(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, const char *name, void *value, size_t size) { + if (fuse_is_bad(inode)) + return -EIO; + return fuse_getxattr(inode, name, value, size); } @@ -186,6 +192,9 @@ static int fuse_xattr_set(const struct xattr_handler *handler, const char *name, const void *value, size_t size, int flags) { + if (fuse_is_bad(inode)) + return -EIO; + if (!value) return fuse_removexattr(inode, name);