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authorPavel Begunkov <asml.silence@gmail.com>2023-09-14 18:51:09 +0300
committerJens Axboe <axboe@kernel.dk>2023-09-14 19:12:55 +0300
commitc21a8027ad8a68c340d0d58bf1cc61dcb0bc4d2f (patch)
tree840d2d18d307e2332f7a498ac854737e2621e66d /io_uring
parent0bb80ecc33a8fb5a682236443c1e740d5c917d1d (diff)
downloadlinux-c21a8027ad8a68c340d0d58bf1cc61dcb0bc4d2f.tar.xz
io_uring/net: fix iter retargeting for selected buf
When using selected buffer feature, io_uring delays data iter setup until later. If io_setup_async_msg() is called before that it might see not correctly setup iterator. Pre-init nr_segs and judge from its state whether we repointing. Cc: stable@vger.kernel.org Reported-by: syzbot+a4c6e5ef999b68b26ed1@syzkaller.appspotmail.com Fixes: 0455d4ccec548 ("io_uring: add POLL_FIRST support for send/sendmsg and recv/recvmsg") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0000000000002770be06053c7757@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
-rw-r--r--io_uring/net.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/io_uring/net.c b/io_uring/net.c
index 3d07bf79c1e0..7a8e298af81b 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -183,6 +183,10 @@ static int io_setup_async_msg(struct io_kiocb *req,
memcpy(async_msg, kmsg, sizeof(*kmsg));
if (async_msg->msg.msg_name)
async_msg->msg.msg_name = &async_msg->addr;
+
+ if ((req->flags & REQ_F_BUFFER_SELECT) && !async_msg->msg.msg_iter.nr_segs)
+ return -EAGAIN;
+
/* if were using fast_iov, set it to the new one */
if (iter_is_iovec(&kmsg->msg.msg_iter) && !kmsg->free_iov) {
size_t fast_idx = iter_iov(&kmsg->msg.msg_iter) - kmsg->fast_iov;
@@ -542,6 +546,7 @@ static int io_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
iomsg->msg.msg_name = &iomsg->addr;
+ iomsg->msg.msg_iter.nr_segs = 0;
#ifdef CONFIG_COMPAT
if (req->ctx->compat)