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authorChangli Gao <xiaosuo@gmail.com>2009-11-04 11:09:52 +0300
committerJens Axboe <jens.axboe@oracle.com>2009-11-04 11:09:52 +0300
commitcc56f7de7f00d188c7c4da1e9861581853b9e92f (patch)
tree4794c8e5b7c7aec176f695dfc9d723d4a73e3ba9
parentf21121cde6e617b90cd03ce083652ca543004dc2 (diff)
downloadlinux-cc56f7de7f00d188c7c4da1e9861581853b9e92f.tar.xz
sendfile(): check f_op.splice_write() rather than f_op.sendpage()
sendfile(2) was reworked with the splice infrastructure, but it still checks f_op.sendpage() instead of f_op.splice_write() wrongly. Although if f_op.sendpage() exists, f_op.splice_write() always exists at the same time currently, the assumption will be broken in future silently. This patch also brings a side effect: sendfile(2) can work with any output file. Some security checks related to f_op are added too. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--fs/read_write.c2
-rw-r--r--fs/splice.c24
2 files changed, 15 insertions, 11 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index 3ac28987f22a..b7f4a1f94d48 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -826,8 +826,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
if (!(out_file->f_mode & FMODE_WRITE))
goto fput_out;
retval = -EINVAL;
- if (!out_file->f_op || !out_file->f_op->sendpage)
- goto fput_out;
in_inode = in_file->f_path.dentry->d_inode;
out_inode = out_file->f_path.dentry->d_inode;
retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count);
diff --git a/fs/splice.c b/fs/splice.c
index 7394e9e17534..39208663aaf1 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -648,9 +648,11 @@ static int pipe_to_sendpage(struct pipe_inode_info *pipe,
ret = buf->ops->confirm(pipe, buf);
if (!ret) {
more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len;
-
- ret = file->f_op->sendpage(file, buf->page, buf->offset,
- sd->len, &pos, more);
+ if (file->f_op && file->f_op->sendpage)
+ ret = file->f_op->sendpage(file, buf->page, buf->offset,
+ sd->len, &pos, more);
+ else
+ ret = -EINVAL;
}
return ret;
@@ -1068,8 +1070,9 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
if (unlikely(ret < 0))
return ret;
- splice_write = out->f_op->splice_write;
- if (!splice_write)
+ if (out->f_op && out->f_op->splice_write)
+ splice_write = out->f_op->splice_write;
+ else
splice_write = default_file_splice_write;
return splice_write(pipe, out, ppos, len, flags);
@@ -1093,8 +1096,9 @@ static long do_splice_to(struct file *in, loff_t *ppos,
if (unlikely(ret < 0))
return ret;
- splice_read = in->f_op->splice_read;
- if (!splice_read)
+ if (in->f_op && in->f_op->splice_read)
+ splice_read = in->f_op->splice_read;
+ else
splice_read = default_file_splice_read;
return splice_read(in, ppos, pipe, len, flags);
@@ -1316,7 +1320,8 @@ static long do_splice(struct file *in, loff_t __user *off_in,
if (off_in)
return -ESPIPE;
if (off_out) {
- if (out->f_op->llseek == no_llseek)
+ if (!out->f_op || !out->f_op->llseek ||
+ out->f_op->llseek == no_llseek)
return -EINVAL;
if (copy_from_user(&offset, off_out, sizeof(loff_t)))
return -EFAULT;
@@ -1336,7 +1341,8 @@ static long do_splice(struct file *in, loff_t __user *off_in,
if (off_out)
return -ESPIPE;
if (off_in) {
- if (in->f_op->llseek == no_llseek)
+ if (!in->f_op || !in->f_op->llseek ||
+ in->f_op->llseek == no_llseek)
return -EINVAL;
if (copy_from_user(&offset, off_in, sizeof(loff_t)))
return -EFAULT;