linux-stable/io_uring/nop.c
Jens Axboe ee116574de io_uring/nop: ensure nop->fd is always initialized
A previous commit added file support for nop, but it only initializes
nop->fd if IORING_NOP_FIXED_FILE is set. That check should be
IORING_NOP_FILE. Fix up the condition in nop preparation, and initialize
it to a sane value even if we're not going to be directly using it.

While in there, do the same thing for the nop->buffer field.

Reported-by: syzbot+9a8500a45c2cabdf9577@syzkaller.appspotmail.com
Fixes: a85f31052b ("io_uring/nop: add support for testing registered files and buffers")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-21 07:15:30 -07:00

85 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/io_uring.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "rsrc.h"
#include "nop.h"
struct io_nop {
/* NOTE: kiocb has the file as the first member, so don't do it here */
struct file *file;
int result;
int fd;
int buffer;
unsigned int flags;
};
#define NOP_FLAGS (IORING_NOP_INJECT_RESULT | IORING_NOP_FIXED_FILE | \
IORING_NOP_FIXED_BUFFER | IORING_NOP_FILE)
int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);
nop->flags = READ_ONCE(sqe->nop_flags);
if (nop->flags & ~NOP_FLAGS)
return -EINVAL;
if (nop->flags & IORING_NOP_INJECT_RESULT)
nop->result = READ_ONCE(sqe->len);
else
nop->result = 0;
if (nop->flags & IORING_NOP_FILE)
nop->fd = READ_ONCE(sqe->fd);
else
nop->fd = -1;
if (nop->flags & IORING_NOP_FIXED_BUFFER)
nop->buffer = READ_ONCE(sqe->buf_index);
else
nop->buffer = -1;
return 0;
}
int io_nop(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);
int ret = nop->result;
if (nop->flags & IORING_NOP_FILE) {
if (nop->flags & IORING_NOP_FIXED_FILE) {
req->file = io_file_get_fixed(req, nop->fd, issue_flags);
req->flags |= REQ_F_FIXED_FILE;
} else {
req->file = io_file_get_normal(req, nop->fd);
}
if (!req->file) {
ret = -EBADF;
goto done;
}
}
if (nop->flags & IORING_NOP_FIXED_BUFFER) {
struct io_ring_ctx *ctx = req->ctx;
struct io_rsrc_node *node;
ret = -EFAULT;
io_ring_submit_lock(ctx, issue_flags);
node = io_rsrc_node_lookup(&ctx->buf_table, nop->buffer);
if (node) {
io_req_assign_buf_node(req, node);
ret = 0;
}
io_ring_submit_unlock(ctx, issue_flags);
}
done:
if (ret < 0)
req_set_fail(req);
io_req_set_res(req, nop->result, 0);
return IOU_OK;
}