diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2018-07-26 16:13:11 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-05 09:26:38 +0200 |
| commit | 7d392674443cb561b2b9161d47198d3428b49d7c (patch) | |
| tree | 71b1567f7955c547f38a750e0b7638ca62d6521d | |
| parent | eaebcf902ae0260b9f9b5bacdc4530c164ca114f (diff) | |
fuse: fix initial parallel dirops
commit 63576c13bd17848376c8ba4a98f5d5151140c4ac upstream.
If parallel dirops are enabled in FUSE_INIT reply, then first operation may
leave fi->mutex held.
Reported-by: syzbot <syzbot+3f7b29af1baa9d0a55be@syzkaller.appspotmail.com>
Fixes: 5c672ab3f0ee ("fuse: serialize dirops by default")
Cc: <stable@vger.kernel.org> # v4.7
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/fuse/dir.c | 10 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 4 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 14 |
3 files changed, 18 insertions, 10 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 7a980b4462d9..29868c35c19a 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -355,11 +355,12 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, struct inode *inode; struct dentry *newent; bool outarg_valid = true; + bool locked; - fuse_lock_inode(dir); + locked = fuse_lock_inode(dir); err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, &outarg, &inode); - fuse_unlock_inode(dir); + fuse_unlock_inode(dir, locked); if (err == -ENOENT) { outarg_valid = false; err = 0; @@ -1332,6 +1333,7 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx) struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_req *req; u64 attr_version = 0; + bool locked; if (is_bad_inode(inode)) return -EIO; @@ -1359,9 +1361,9 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx) fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, FUSE_READDIR); } - fuse_lock_inode(inode); + locked = fuse_lock_inode(inode); fuse_request_send(fc, req); - fuse_unlock_inode(inode); + fuse_unlock_inode(inode, locked); nbytes = req->out.args[0].size; err = req->out.h.error; fuse_put_request(fc, req); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index d5773ca67ad2..d71ef3b8354d 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -964,8 +964,8 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, void fuse_set_initialized(struct fuse_conn *fc); -void fuse_unlock_inode(struct inode *inode); -void fuse_lock_inode(struct inode *inode); +void fuse_unlock_inode(struct inode *inode, bool locked); +bool fuse_lock_inode(struct inode *inode); int fuse_setxattr(struct inode *inode, const char *name, const void *value, size_t size, int flags); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index a13ecefa9cd1..25fdf220d2e9 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -357,15 +357,21 @@ int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid, return 0; } -void fuse_lock_inode(struct inode *inode) +bool fuse_lock_inode(struct inode *inode) { - if (!get_fuse_conn(inode)->parallel_dirops) + bool locked = false; + + if (!get_fuse_conn(inode)->parallel_dirops) { mutex_lock(&get_fuse_inode(inode)->mutex); + locked = true; + } + + return locked; } -void fuse_unlock_inode(struct inode *inode) +void fuse_unlock_inode(struct inode *inode, bool locked) { - if (!get_fuse_conn(inode)->parallel_dirops) + if (locked) mutex_unlock(&get_fuse_inode(inode)->mutex); } |