Commit 7572777e authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: verify ioctl retries



Verify that the total length of the iovec returned in FUSE_IOCTL_RETRY
doesn't overflow iov_length().
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
CC: Tejun Heo <tj@kernel.org>
CC: <stable@kernel.org>         [2.6.31+]
parent d9d318d3
......@@ -1666,6 +1666,20 @@ static int fuse_copy_ioctl_iovec(struct iovec *dst, void *src,
return 0;
}
/* Make sure iov_length() won't overflow */
static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
{
size_t n;
u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
for (n = 0; n < count; n++) {
if (iov->iov_len > (size_t) max)
return -ENOMEM;
max -= iov->iov_len;
}
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
......@@ -1858,6 +1872,14 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
in_iov = page_address(iov_page);
out_iov = in_iov + in_iovs;
err = fuse_verify_ioctl_iov(in_iov, in_iovs);
if (err)
goto out;
err = fuse_verify_ioctl_iov(out_iov, out_iovs);
if (err)
goto out;
goto retry;
}
......
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