提交 1baa26b2 编写于 作者: M Miklos Szeredi

fuse: fix ioctl ABI

In kernel ABI version 7.16 and later FUSE_IOCTL_RETRY reply from a
unrestricted IOCTL request shall return with an array of 'struct
fuse_ioctl_iovec' instead of 'struct iovec'.  This fixes the ABI
ambiguity of 32bit vs. 64bit.
Reported-by: N"ccmail111" <ccmail111@yahoo.com>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
CC: Tejun Heo <tj@kernel.org>
上级 02c048b9
......@@ -1634,9 +1634,9 @@ static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
* and 64bit. Fortunately we can determine which structure the server
* used from the size of the reply.
*/
static int fuse_copy_ioctl_iovec(struct iovec *dst, void *src,
size_t transferred, unsigned count,
bool is_compat)
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) {
......@@ -1680,6 +1680,42 @@ static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
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
......@@ -1746,8 +1782,15 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
size_t in_size, out_size, transferred;
int err;
#if BITS_PER_LONG == 32
inarg.flags |= FUSE_IOCTL_32BIT;
#else
if (flags & FUSE_IOCTL_COMPAT)
inarg.flags |= FUSE_IOCTL_32BIT;
#endif
/* assume all the iovs returned by client always fits in a page */
BUILD_BUG_ON(sizeof(struct iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
err = -ENOMEM;
pages = kzalloc(sizeof(pages[0]) * FUSE_MAX_PAGES_PER_REQ, GFP_KERNEL);
......@@ -1862,7 +1905,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
goto out;
vaddr = kmap_atomic(pages[0], KM_USER0);
err = fuse_copy_ioctl_iovec(iov_page, vaddr,
err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
transferred, in_iovs + out_iovs,
(flags & FUSE_IOCTL_COMPAT) != 0);
kunmap_atomic(vaddr, KM_USER0);
......
......@@ -44,6 +44,9 @@
*
* 7.16
* - add BATCH_FORGET request
* - FUSE_IOCTL_UNRESTRICTED shall now return with array of 'struct
* fuse_ioctl_iovec' instead of ambiguous 'struct iovec'
* - add FUSE_IOCTL_32BIT flag
*/
#ifndef _LINUX_FUSE_H
......@@ -203,12 +206,14 @@ struct fuse_file_lock {
* FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
* FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
* FUSE_IOCTL_RETRY: retry with new iovecs
* FUSE_IOCTL_32BIT: 32bit ioctl
*
* FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
*/
#define FUSE_IOCTL_COMPAT (1 << 0)
#define FUSE_IOCTL_UNRESTRICTED (1 << 1)
#define FUSE_IOCTL_RETRY (1 << 2)
#define FUSE_IOCTL_32BIT (1 << 3)
#define FUSE_IOCTL_MAX_IOV 256
......@@ -524,6 +529,11 @@ struct fuse_ioctl_in {
__u32 out_size;
};
struct fuse_ioctl_iovec {
__u64 base;
__u64 len;
};
struct fuse_ioctl_out {
__s32 result;
__u32 flags;
......
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