splice: move f_mode checks to do_{splice,tee}()

do_splice() is used by io_uring, as will be do_tee(). Move f_mode
checks from sys_{splice,tee}() to do_{splice,tee}(), so they're
enforced for io_uring as well.

Fixes: 7d67af2c01 ("io_uring: add splice(2) support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-05-04 22:39:35 +03:00 committed by Jens Axboe
parent 7f13657d14
commit 90da2e3f25

View File

@ -1118,6 +1118,10 @@ long do_splice(struct file *in, loff_t __user *off_in,
loff_t offset;
long ret;
if (unlikely(!(in->f_mode & FMODE_READ) ||
!(out->f_mode & FMODE_WRITE)))
return -EBADF;
ipipe = get_pipe_info(in);
opipe = get_pipe_info(out);
@ -1125,12 +1129,6 @@ long do_splice(struct file *in, loff_t __user *off_in,
if (off_in || off_out)
return -ESPIPE;
if (!(in->f_mode & FMODE_READ))
return -EBADF;
if (!(out->f_mode & FMODE_WRITE))
return -EBADF;
/* Splicing to self would be fun, but... */
if (ipipe == opipe)
return -EINVAL;
@ -1153,9 +1151,6 @@ long do_splice(struct file *in, loff_t __user *off_in,
offset = out->f_pos;
}
if (unlikely(!(out->f_mode & FMODE_WRITE)))
return -EBADF;
if (unlikely(out->f_flags & O_APPEND))
return -EINVAL;
@ -1440,15 +1435,11 @@ SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in,
error = -EBADF;
in = fdget(fd_in);
if (in.file) {
if (in.file->f_mode & FMODE_READ) {
out = fdget(fd_out);
if (out.file) {
if (out.file->f_mode & FMODE_WRITE)
error = do_splice(in.file, off_in,
out.file, off_out,
len, flags);
fdput(out);
}
out = fdget(fd_out);
if (out.file) {
error = do_splice(in.file, off_in, out.file, off_out,
len, flags);
fdput(out);
}
fdput(in);
}
@ -1770,6 +1761,10 @@ static long do_tee(struct file *in, struct file *out, size_t len,
struct pipe_inode_info *opipe = get_pipe_info(out);
int ret = -EINVAL;
if (unlikely(!(in->f_mode & FMODE_READ) ||
!(out->f_mode & FMODE_WRITE)))
return -EBADF;
/*
* Duplicate the contents of ipipe to opipe without actually
* copying the data.
@ -1795,7 +1790,7 @@ static long do_tee(struct file *in, struct file *out, size_t len,
SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
{
struct fd in;
struct fd in, out;
int error;
if (unlikely(flags & ~SPLICE_F_ALL))
@ -1807,14 +1802,10 @@ SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
error = -EBADF;
in = fdget(fdin);
if (in.file) {
if (in.file->f_mode & FMODE_READ) {
struct fd out = fdget(fdout);
if (out.file) {
if (out.file->f_mode & FMODE_WRITE)
error = do_tee(in.file, out.file,
len, flags);
fdput(out);
}
out = fdget(fdout);
if (out.file) {
error = do_tee(in.file, out.file, len, flags);
fdput(out);
}
fdput(in);
}