Merge 5e20208dfe ("fuse: fix memory leak in fuse_create_open") into android14-6.1-lts

Steps on the way to 6.1.110

Resolves merge conflicts in:
	fs/fuse/fuse_i.h

Change-Id: Iee80d4790e074e54560b9c6cb9949474e4217346
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

fs/fuse/dev.c

@@ -490,6 +490,8 @@ static void fuse_args_to_req(struct fuse_req *req, struct fuse_args *args)
 	req->in.h.nodeid = args->nodeid;
 	req->in.h.padding = args->error_in;
 	req->args = args;
+	if (args->is_ext)
+		req->in.h.total_extlen = args->in_args[args->ext_idx].size / 8;
 	if (args->end)
 		__set_bit(FR_ASYNC, &req->flags);
 }
@@ -1512,7 +1514,7 @@ static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
 	buf[outarg.namelen] = 0;
 
 	down_read(&fc->killsb);
-	err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name);
+	err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name, outarg.flags);
 	up_read(&fc->killsb);
 	kfree(buf);
 	return err;
@@ -1560,7 +1562,7 @@ static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
 	buf[outarg.namelen] = 0;
 
 	down_read(&fc->killsb);
-	err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name);
+	err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name, 0);
 	up_read(&fc->killsb);
 	kfree(buf);
 	return err;

fs/fuse/dir.c

@@ -662,7 +662,7 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 }
 
 static int get_security_context(struct dentry *entry, umode_t mode,
-				void **security_ctx, u32 *security_ctxlen)
+				struct fuse_in_arg *ext)
 {
 	struct fuse_secctx *fctx;
 	struct fuse_secctx_header *header;
@@ -709,14 +709,42 @@ static int get_security_context(struct dentry *entry, umode_t mode,
 
 		memcpy(ptr, ctx, ctxlen);
 	}
-	*security_ctxlen = total_len;
-	*security_ctx = header;
+	ext->size = total_len;
+	ext->value = header;
 	err = 0;
 out_err:
 	kfree(ctx);
 	return err;
 }
 
+static int get_create_ext(struct fuse_args *args, struct dentry *dentry,
+			  umode_t mode)
+{
+	struct fuse_conn *fc = get_fuse_conn_super(dentry->d_sb);
+	struct fuse_in_arg ext = { .size = 0, .value = NULL };
+	int err = 0;
+
+	if (fc->init_security)
+		err = get_security_context(dentry, mode, &ext);
+
+	if (!err && ext.size) {
+		WARN_ON(args->in_numargs >= ARRAY_SIZE(args->in_args));
+		args->is_ext = true;
+		args->ext_idx = args->in_numargs++;
+		args->in_args[args->ext_idx] = ext;
+	} else {
+		kfree(ext.value);
+	}
+
+	return err;
+}
+
+static void free_ext_value(struct fuse_args *args)
+{
+	if (args->is_ext)
+		kfree(args->in_args[args->ext_idx].value);
+}
+
 /*
  * Atomic create+open operation
  *
@@ -738,8 +766,6 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	struct fuse_entry_out outentry;
 	struct fuse_inode *fi;
 	struct fuse_file *ff;
-	void *security_ctx = NULL;
-	u32 security_ctxlen;
 	bool trunc = flags & O_TRUNC;
 
 	/* Userspace expects S_IFREG in create mode */
@@ -797,19 +823,12 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	args.out_args[1].size = sizeof(outopen);
 	args.out_args[1].value = &outopen;
 
-	if (fm->fc->init_security) {
-		err = get_security_context(entry, mode, &security_ctx,
-					   &security_ctxlen);
-		if (err)
-			goto out_put_forget_req;
-
-		args.in_numargs = 3;
-		args.in_args[2].size = security_ctxlen;
-		args.in_args[2].value = security_ctx;
-	}
+	err = get_create_ext(&args, entry, mode);
+	if (err)
+		goto out_free_ff;
 
 	err = fuse_simple_request(fm, &args);
-	kfree(security_ctx);
+	free_ext_value(&args);
 	if (err)
 		goto out_free_ff;
 
@@ -917,8 +936,6 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
 	struct dentry *d;
 	int err;
 	struct fuse_forget_link *forget;
-	void *security_ctx = NULL;
-	u32 security_ctxlen;
 
 	if (fuse_is_bad(dir))
 		return -EIO;
@@ -933,21 +950,14 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
 	args->out_args[0].size = sizeof(outarg);
 	args->out_args[0].value = &outarg;
 
-	if (fm->fc->init_security && args->opcode != FUSE_LINK) {
-		err = get_security_context(entry, mode, &security_ctx,
-					   &security_ctxlen);
+	if (args->opcode != FUSE_LINK) {
+		err = get_create_ext(args, entry, mode);
 		if (err)
 			goto out_put_forget_req;
-
-		BUG_ON(args->in_numargs != 2);
-
-		args->in_numargs = 3;
-		args->in_args[2].size = security_ctxlen;
-		args->in_args[2].value = security_ctx;
 	}
 
 	err = fuse_simple_request(fm, args);
-	kfree(security_ctx);
+	free_ext_value(args);
 	if (err)
 		goto out_put_forget_req;
 
@@ -1479,7 +1489,7 @@ int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask)
 }
 
 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
-			     u64 child_nodeid, struct qstr *name)
+			     u64 child_nodeid, struct qstr *name, u32 flags)
 {
 	int err = -ENOTDIR;
 	struct inode *parent;
@@ -1506,7 +1516,9 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
 		goto unlock;
 
 	fuse_dir_changed(parent);
-	fuse_invalidate_entry(entry);
+	if (!(flags & FUSE_EXPIRE_ONLY))
+		d_invalidate(entry);
+	fuse_invalidate_entry_cache(entry);
 
 	if (child_nodeid != 0 && d_really_is_positive(entry)) {
 		inode_lock(d_inode(entry));

fs/fuse/file.c

@@ -1629,14 +1629,47 @@ static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	return res;
 }
 
+static bool fuse_direct_write_extending_i_size(struct kiocb *iocb,
+					       struct iov_iter *iter)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+
+	return iocb->ki_pos + iov_iter_count(iter) > i_size_read(inode);
+}
+
 static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	struct inode *inode = file_inode(iocb->ki_filp);
+	struct file *file = iocb->ki_filp;
+	struct fuse_file *ff = file->private_data;
 	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
 	ssize_t res;
+	bool exclusive_lock =
+		!(ff->open_flags & FOPEN_PARALLEL_DIRECT_WRITES) ||
+		iocb->ki_flags & IOCB_APPEND ||
+		fuse_direct_write_extending_i_size(iocb, from);
+
+	/*
+	 * Take exclusive lock if
+	 * - Parallel direct writes are disabled - a user space decision
+	 * - Parallel direct writes are enabled and i_size is being extended.
+	 *   This might not be needed at all, but needs further investigation.
+	 */
+	if (exclusive_lock)
+		inode_lock(inode);
+	else {
+		inode_lock_shared(inode);
+
+		/* A race with truncate might have come up as the decision for
+		 * the lock type was done without holding the lock, check again.
+		 */
+		if (fuse_direct_write_extending_i_size(iocb, from)) {
+			inode_unlock_shared(inode);
+			inode_lock(inode);
+			exclusive_lock = true;
+		}
+	}
 
-	/* Don't allow parallel writes to the same file */
-	inode_lock(inode);
 	res = generic_write_checks(iocb, from);
 	if (res > 0) {
 		if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
@@ -1647,7 +1680,10 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
 			fuse_write_update_attr(inode, iocb->ki_pos, res);
 		}
 	}
-	inode_unlock(inode);
+	if (exclusive_lock)
+		inode_unlock(inode);
+	else
+		inode_unlock_shared(inode);
 
 	return res;
 }
@@ -3074,6 +3110,7 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 
 	if (iov_iter_rw(iter) == WRITE) {
 		fuse_write_update_attr(inode, pos, ret);
+		/* For extending writes we already hold exclusive lock */
 		if (ret < 0 && offset + count > i_size)
 			fuse_do_truncate(file);
 	}

fs/fuse/fuse_i.h

@@ -345,8 +345,9 @@ struct fuse_args {
 	uint64_t nodeid;
 	uint32_t opcode;
 	uint32_t error_in;
-	unsigned short in_numargs;
-	unsigned short out_numargs;
+	uint8_t in_numargs;
+	uint8_t out_numargs;
+	uint8_t ext_idx;
 	bool force:1;
 	bool noreply:1;
 	bool nocreds:1;
@@ -357,6 +358,7 @@ struct fuse_args {
 	bool page_zeroing:1;
 	bool page_replace:1;
 	bool may_block:1;
+	bool is_ext:1;
 	struct fuse_in_arg in_args[FUSE_MAX_IN_ARGS];
 	struct fuse_arg out_args[FUSE_MAX_OUT_ARGS];
 	void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
@@ -1339,7 +1341,7 @@ int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
  * then the dentry is unhashed (d_delete()).
  */
 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
-			     u64 child_nodeid, struct qstr *name);
+			     u64 child_nodeid, struct qstr *name, u32 flags);
 
 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
 		 bool isdir);

include/uapi/linux/fuse.h

@@ -197,6 +197,13 @@
  *
  *  7.37
  *  - add FUSE_TMPFILE
+ *
+ *  7.38
+ *  - add FUSE_EXPIRE_ONLY flag to fuse_notify_inval_entry
+ *  - add FOPEN_PARALLEL_DIRECT_WRITES
+ *  - add total_extlen to fuse_in_header
+ *  - add FUSE_MAX_NR_SECCTX
+ *  - add extension header
  */
 
 #ifndef _LINUX_FUSE_H
@@ -232,7 +239,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 37
+#define FUSE_KERNEL_MINOR_VERSION 38
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -304,6 +311,7 @@ struct fuse_file_lock {
  * FOPEN_CACHE_DIR: allow caching this directory
  * FOPEN_STREAM: the file is stream-like (no file position at all)
  * FOPEN_NOFLUSH: don't flush data cache on close (unless FUSE_WRITEBACK_CACHE)
+ * FOPEN_PARALLEL_DIRECT_WRITES: Allow concurrent direct writes on the same inode
  */
 #define FOPEN_DIRECT_IO		(1 << 0)
 #define FOPEN_KEEP_CACHE	(1 << 1)
@@ -311,6 +319,7 @@ struct fuse_file_lock {
 #define FOPEN_CACHE_DIR		(1 << 3)
 #define FOPEN_STREAM		(1 << 4)
 #define FOPEN_NOFLUSH		(1 << 5)
+#define FOPEN_PARALLEL_DIRECT_WRITES	(1 << 6)
 
 /**
  * INIT request/reply flags
@@ -503,6 +512,21 @@ struct fuse_file_lock {
  */
 #define FUSE_SETXATTR_ACL_KILL_SGID	(1 << 0)
 
+/**
+ * notify_inval_entry flags
+ * FUSE_EXPIRE_ONLY
+ */
+#define FUSE_EXPIRE_ONLY		(1 << 0)
+
+/**
+ * extension type
+ * FUSE_MAX_NR_SECCTX: maximum value of &fuse_secctx_header.nr_secctx
+ */
+enum fuse_ext_type {
+	/* Types 0..31 are reserved for fuse_secctx_header */
+	FUSE_MAX_NR_SECCTX	= 31,
+};
+
 enum fuse_opcode {
 	FUSE_LOOKUP		= 1,
 	FUSE_FORGET		= 2,  /* no reply */
@@ -887,7 +911,8 @@ struct fuse_in_header {
 	uint32_t	uid;
 	uint32_t	gid;
 	uint32_t	pid;
-	uint32_t	padding;
+	uint16_t	total_extlen; /* length of extensions in 8byte units */
+	uint16_t	padding;
 };
 
 struct fuse_out_header {
@@ -932,7 +957,7 @@ struct fuse_notify_inval_inode_out {
 struct fuse_notify_inval_entry_out {
 	uint64_t	parent;
 	uint32_t	namelen;
-	uint32_t	padding;
+	uint32_t	flags;
 };
 
 struct fuse_notify_delete_out {
@@ -1051,4 +1076,17 @@ struct fuse_secctx_header {
 	uint32_t	nr_secctx;
 };
 
+/**
+ * struct fuse_ext_header - extension header
+ * @size: total size of this extension including this header
+ * @type: type of extension
+ *
+ * This is made compatible with fuse_secctx_header by using type values >
+ * FUSE_MAX_NR_SECCTX
+ */
+struct fuse_ext_header {
+	uint32_t	size;
+	uint32_t	type;
+};
+
 #endif /* _LINUX_FUSE_H */