From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- fs/fuse/ioctl.c | 515 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 515 insertions(+) create mode 100644 fs/fuse/ioctl.c (limited to 'fs/fuse/ioctl.c') diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c new file mode 100644 index 0000000000..726640fa43 --- /dev/null +++ b/fs/fuse/ioctl.c @@ -0,0 +1,515 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017 Red Hat, Inc. + */ + +#include "fuse_i.h" + +#include +#include +#include + +static ssize_t fuse_send_ioctl(struct fuse_mount *fm, struct fuse_args *args, + struct fuse_ioctl_out *outarg) +{ + ssize_t ret; + + args->out_args[0].size = sizeof(*outarg); + args->out_args[0].value = outarg; + + ret = fuse_simple_request(fm, args); + + /* Translate ENOSYS, which shouldn't be returned from fs */ + if (ret == -ENOSYS) + ret = -ENOTTY; + + if (ret >= 0 && outarg->result == -ENOSYS) + outarg->result = -ENOTTY; + + return ret; +} + +/* + * CUSE servers compiled on 32bit broke on 64bit kernels because the + * ABI was defined to be 'struct iovec' which is different on 32bit + * and 64bit. Fortunately we can determine which structure the server + * used from the size of the reply. + */ +static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, + size_t transferred, unsigned count, + bool is_compat) +{ +#ifdef CONFIG_COMPAT + if (count * sizeof(struct compat_iovec) == transferred) { + struct compat_iovec *ciov = src; + unsigned i; + + /* + * With this interface a 32bit server cannot support + * non-compat (i.e. ones coming from 64bit apps) ioctl + * requests + */ + if (!is_compat) + return -EINVAL; + + for (i = 0; i < count; i++) { + dst[i].iov_base = compat_ptr(ciov[i].iov_base); + dst[i].iov_len = ciov[i].iov_len; + } + return 0; + } +#endif + + if (count * sizeof(struct iovec) != transferred) + return -EIO; + + memcpy(dst, src, transferred); + return 0; +} + +/* Make sure iov_length() won't overflow */ +static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov, + size_t count) +{ + size_t n; + u32 max = fc->max_pages << PAGE_SHIFT; + + for (n = 0; n < count; n++, iov++) { + if (iov->iov_len > (size_t) max) + return -ENOMEM; + max -= iov->iov_len; + } + return 0; +} + +static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst, + void *src, size_t transferred, unsigned count, + bool is_compat) +{ + unsigned i; + struct fuse_ioctl_iovec *fiov = src; + + if (fc->minor < 16) { + return fuse_copy_ioctl_iovec_old(dst, src, transferred, + count, is_compat); + } + + if (count * sizeof(struct fuse_ioctl_iovec) != transferred) + return -EIO; + + for (i = 0; i < count; i++) { + /* Did the server supply an inappropriate value? */ + if (fiov[i].base != (unsigned long) fiov[i].base || + fiov[i].len != (unsigned long) fiov[i].len) + return -EIO; + + dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base; + dst[i].iov_len = (size_t) fiov[i].len; + +#ifdef CONFIG_COMPAT + if (is_compat && + (ptr_to_compat(dst[i].iov_base) != fiov[i].base || + (compat_size_t) dst[i].iov_len != fiov[i].len)) + return -EIO; +#endif + } + + return 0; +} + + +/* + * For ioctls, there is no generic way to determine how much memory + * needs to be read and/or written. Furthermore, ioctls are allowed + * to dereference the passed pointer, so the parameter requires deep + * copying but FUSE has no idea whatsoever about what to copy in or + * out. + * + * This is solved by allowing FUSE server to retry ioctl with + * necessary in/out iovecs. Let's assume the ioctl implementation + * needs to read in the following structure. + * + * struct a { + * char *buf; + * size_t buflen; + * } + * + * On the first callout to FUSE server, inarg->in_size and + * inarg->out_size will be NULL; then, the server completes the ioctl + * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and + * the actual iov array to + * + * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } } + * + * which tells FUSE to copy in the requested area and retry the ioctl. + * On the second round, the server has access to the structure and + * from that it can tell what to look for next, so on the invocation, + * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to + * + * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) }, + * { .iov_base = a.buf, .iov_len = a.buflen } } + * + * FUSE will copy both struct a and the pointed buffer from the + * process doing the ioctl and retry ioctl with both struct a and the + * buffer. + * + * This time, FUSE server has everything it needs and completes ioctl + * without FUSE_IOCTL_RETRY which finishes the ioctl call. + * + * Copying data out works the same way. + * + * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel + * automatically initializes in and out iovs by decoding @cmd with + * _IOC_* macros and the server is not allowed to request RETRY. This + * limits ioctl data transfers to well-formed ioctls and is the forced + * behavior for all FUSE servers. + */ +long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, + unsigned int flags) +{ + struct fuse_file *ff = file->private_data; + struct fuse_mount *fm = ff->fm; + struct fuse_ioctl_in inarg = { + .fh = ff->fh, + .cmd = cmd, + .arg = arg, + .flags = flags + }; + struct fuse_ioctl_out outarg; + struct iovec *iov_page = NULL; + struct iovec *in_iov = NULL, *out_iov = NULL; + unsigned int in_iovs = 0, out_iovs = 0, max_pages; + size_t in_size, out_size, c; + ssize_t transferred; + int err, i; + struct iov_iter ii; + struct fuse_args_pages ap = {}; + +#if BITS_PER_LONG == 32 + inarg.flags |= FUSE_IOCTL_32BIT; +#else + if (flags & FUSE_IOCTL_COMPAT) { + inarg.flags |= FUSE_IOCTL_32BIT; +#ifdef CONFIG_X86_X32_ABI + if (in_x32_syscall()) + inarg.flags |= FUSE_IOCTL_COMPAT_X32; +#endif + } +#endif + + /* assume all the iovs returned by client always fits in a page */ + BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); + + err = -ENOMEM; + ap.pages = fuse_pages_alloc(fm->fc->max_pages, GFP_KERNEL, &ap.descs); + iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); + if (!ap.pages || !iov_page) + goto out; + + fuse_page_descs_length_init(ap.descs, 0, fm->fc->max_pages); + + /* + * If restricted, initialize IO parameters as encoded in @cmd. + * RETRY from server is not allowed. + */ + if (!(flags & FUSE_IOCTL_UNRESTRICTED)) { + struct iovec *iov = iov_page; + + iov->iov_base = (void __user *)arg; + iov->iov_len = _IOC_SIZE(cmd); + + if (_IOC_DIR(cmd) & _IOC_WRITE) { + in_iov = iov; + in_iovs = 1; + } + + if (_IOC_DIR(cmd) & _IOC_READ) { + out_iov = iov; + out_iovs = 1; + } + } + + retry: + inarg.in_size = in_size = iov_length(in_iov, in_iovs); + inarg.out_size = out_size = iov_length(out_iov, out_iovs); + + /* + * Out data can be used either for actual out data or iovs, + * make sure there always is at least one page. + */ + out_size = max_t(size_t, out_size, PAGE_SIZE); + max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE); + + /* make sure there are enough buffer pages and init request with them */ + err = -ENOMEM; + if (max_pages > fm->fc->max_pages) + goto out; + while (ap.num_pages < max_pages) { + ap.pages[ap.num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); + if (!ap.pages[ap.num_pages]) + goto out; + ap.num_pages++; + } + + + /* okay, let's send it to the client */ + ap.args.opcode = FUSE_IOCTL; + ap.args.nodeid = ff->nodeid; + ap.args.in_numargs = 1; + ap.args.in_args[0].size = sizeof(inarg); + ap.args.in_args[0].value = &inarg; + if (in_size) { + ap.args.in_numargs++; + ap.args.in_args[1].size = in_size; + ap.args.in_pages = true; + + err = -EFAULT; + iov_iter_init(&ii, ITER_SOURCE, in_iov, in_iovs, in_size); + for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { + c = copy_page_from_iter(ap.pages[i], 0, PAGE_SIZE, &ii); + if (c != PAGE_SIZE && iov_iter_count(&ii)) + goto out; + } + } + + ap.args.out_numargs = 2; + ap.args.out_args[1].size = out_size; + ap.args.out_pages = true; + ap.args.out_argvar = true; + + transferred = fuse_send_ioctl(fm, &ap.args, &outarg); + err = transferred; + if (transferred < 0) + goto out; + + /* did it ask for retry? */ + if (outarg.flags & FUSE_IOCTL_RETRY) { + void *vaddr; + + /* no retry if in restricted mode */ + err = -EIO; + if (!(flags & FUSE_IOCTL_UNRESTRICTED)) + goto out; + + in_iovs = outarg.in_iovs; + out_iovs = outarg.out_iovs; + + /* + * Make sure things are in boundary, separate checks + * are to protect against overflow. + */ + err = -ENOMEM; + if (in_iovs > FUSE_IOCTL_MAX_IOV || + out_iovs > FUSE_IOCTL_MAX_IOV || + in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV) + goto out; + + vaddr = kmap_local_page(ap.pages[0]); + err = fuse_copy_ioctl_iovec(fm->fc, iov_page, vaddr, + transferred, in_iovs + out_iovs, + (flags & FUSE_IOCTL_COMPAT) != 0); + kunmap_local(vaddr); + if (err) + goto out; + + in_iov = iov_page; + out_iov = in_iov + in_iovs; + + err = fuse_verify_ioctl_iov(fm->fc, in_iov, in_iovs); + if (err) + goto out; + + err = fuse_verify_ioctl_iov(fm->fc, out_iov, out_iovs); + if (err) + goto out; + + goto retry; + } + + err = -EIO; + if (transferred > inarg.out_size) + goto out; + + err = -EFAULT; + iov_iter_init(&ii, ITER_DEST, out_iov, out_iovs, transferred); + for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { + c = copy_page_to_iter(ap.pages[i], 0, PAGE_SIZE, &ii); + if (c != PAGE_SIZE && iov_iter_count(&ii)) + goto out; + } + err = 0; + out: + free_page((unsigned long) iov_page); + while (ap.num_pages) + __free_page(ap.pages[--ap.num_pages]); + kfree(ap.pages); + + return err ? err : outarg.result; +} +EXPORT_SYMBOL_GPL(fuse_do_ioctl); + +long fuse_ioctl_common(struct file *file, unsigned int cmd, + unsigned long arg, unsigned int flags) +{ + struct inode *inode = file_inode(file); + struct fuse_conn *fc = get_fuse_conn(inode); + + if (!fuse_allow_current_process(fc)) + return -EACCES; + + if (fuse_is_bad(inode)) + return -EIO; + + return fuse_do_ioctl(file, cmd, arg, flags); +} + +long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return fuse_ioctl_common(file, cmd, arg, 0); +} + +long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT); +} + +static int fuse_priv_ioctl(struct inode *inode, struct fuse_file *ff, + unsigned int cmd, void *ptr, size_t size) +{ + struct fuse_mount *fm = ff->fm; + struct fuse_ioctl_in inarg; + struct fuse_ioctl_out outarg; + FUSE_ARGS(args); + int err; + + memset(&inarg, 0, sizeof(inarg)); + inarg.fh = ff->fh; + inarg.cmd = cmd; + +#if BITS_PER_LONG == 32 + inarg.flags |= FUSE_IOCTL_32BIT; +#endif + if (S_ISDIR(inode->i_mode)) + inarg.flags |= FUSE_IOCTL_DIR; + + if (_IOC_DIR(cmd) & _IOC_READ) + inarg.out_size = size; + if (_IOC_DIR(cmd) & _IOC_WRITE) + inarg.in_size = size; + + args.opcode = FUSE_IOCTL; + args.nodeid = ff->nodeid; + args.in_numargs = 2; + args.in_args[0].size = sizeof(inarg); + args.in_args[0].value = &inarg; + args.in_args[1].size = inarg.in_size; + args.in_args[1].value = ptr; + args.out_numargs = 2; + args.out_args[1].size = inarg.out_size; + args.out_args[1].value = ptr; + + err = fuse_send_ioctl(fm, &args, &outarg); + if (!err) { + if (outarg.result < 0) + err = outarg.result; + else if (outarg.flags & FUSE_IOCTL_RETRY) + err = -EIO; + } + return err; +} + +static struct fuse_file *fuse_priv_ioctl_prepare(struct inode *inode) +{ + struct fuse_mount *fm = get_fuse_mount(inode); + bool isdir = S_ISDIR(inode->i_mode); + + if (!fuse_allow_current_process(fm->fc)) + return ERR_PTR(-EACCES); + + if (fuse_is_bad(inode)) + return ERR_PTR(-EIO); + + if (!S_ISREG(inode->i_mode) && !isdir) + return ERR_PTR(-ENOTTY); + + return fuse_file_open(fm, get_node_id(inode), O_RDONLY, isdir); +} + +static void fuse_priv_ioctl_cleanup(struct inode *inode, struct fuse_file *ff) +{ + fuse_file_release(inode, ff, O_RDONLY, NULL, S_ISDIR(inode->i_mode)); +} + +int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa) +{ + struct inode *inode = d_inode(dentry); + struct fuse_file *ff; + unsigned int flags; + struct fsxattr xfa; + int err; + + ff = fuse_priv_ioctl_prepare(inode); + if (IS_ERR(ff)) + return PTR_ERR(ff); + + if (fa->flags_valid) { + err = fuse_priv_ioctl(inode, ff, FS_IOC_GETFLAGS, + &flags, sizeof(flags)); + if (err) + goto cleanup; + + fileattr_fill_flags(fa, flags); + } else { + err = fuse_priv_ioctl(inode, ff, FS_IOC_FSGETXATTR, + &xfa, sizeof(xfa)); + if (err) + goto cleanup; + + fileattr_fill_xflags(fa, xfa.fsx_xflags); + fa->fsx_extsize = xfa.fsx_extsize; + fa->fsx_nextents = xfa.fsx_nextents; + fa->fsx_projid = xfa.fsx_projid; + fa->fsx_cowextsize = xfa.fsx_cowextsize; + } +cleanup: + fuse_priv_ioctl_cleanup(inode, ff); + + return err; +} + +int fuse_fileattr_set(struct mnt_idmap *idmap, + struct dentry *dentry, struct fileattr *fa) +{ + struct inode *inode = d_inode(dentry); + struct fuse_file *ff; + unsigned int flags = fa->flags; + struct fsxattr xfa; + int err; + + ff = fuse_priv_ioctl_prepare(inode); + if (IS_ERR(ff)) + return PTR_ERR(ff); + + if (fa->flags_valid) { + err = fuse_priv_ioctl(inode, ff, FS_IOC_SETFLAGS, + &flags, sizeof(flags)); + if (err) + goto cleanup; + } else { + memset(&xfa, 0, sizeof(xfa)); + xfa.fsx_xflags = fa->fsx_xflags; + xfa.fsx_extsize = fa->fsx_extsize; + xfa.fsx_nextents = fa->fsx_nextents; + xfa.fsx_projid = fa->fsx_projid; + xfa.fsx_cowextsize = fa->fsx_cowextsize; + + err = fuse_priv_ioctl(inode, ff, FS_IOC_FSSETXATTR, + &xfa, sizeof(xfa)); + } + +cleanup: + fuse_priv_ioctl_cleanup(inode, ff); + + return err; +} -- cgit v1.2.3