diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2022-09-26 14:35:09 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-09-26 08:36:50 -0600 |
| commit | 4c17a496a7a0730fdfc9e249b83cc58249111532 (patch) | |
| tree | b1b8ef69df833c6265c4cafdaf43d29b59cd7724 /io_uring | |
| parent | aa1df3a360a0c50e0f0086a785d75c2785c29967 (diff) | |
io_uring/net: fix cleanup double free free_iov init
Having ->async_data doesn't mean it's initialised and previously we vere
relying on setting F_CLEANUP at the right moment. With zc sendmsg
though, we set F_CLEANUP early in prep when we alloc a notif and so we
may allocate async_data, fail in copy_msg_hdr() leaving
struct io_async_msghdr not initialised correctly but with F_CLEANUP
set, which causes a ->free_iov double free and probably other nastiness.
Always initialise ->free_iov. Also, now it might point to fast_iov when
fails, so avoid freeing it during cleanups.
Reported-by: syzbot+edfd15cd4246a3fc615a@syzkaller.appspotmail.com
Fixes: 493108d95f146 ("io_uring/net: zerocopy sendmsg")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/net.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/io_uring/net.c b/io_uring/net.c index 2af56661590a..6b69eff6887e 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -124,20 +124,22 @@ static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req, { struct io_ring_ctx *ctx = req->ctx; struct io_cache_entry *entry; + struct io_async_msghdr *hdr; if (!(issue_flags & IO_URING_F_UNLOCKED) && (entry = io_alloc_cache_get(&ctx->netmsg_cache)) != NULL) { - struct io_async_msghdr *hdr; - hdr = container_of(entry, struct io_async_msghdr, cache); + hdr->free_iov = NULL; req->flags |= REQ_F_ASYNC_DATA; req->async_data = hdr; return hdr; } - if (!io_alloc_async_data(req)) - return req->async_data; - + if (!io_alloc_async_data(req)) { + hdr = req->async_data; + hdr->free_iov = NULL; + return hdr; + } return NULL; } @@ -192,7 +194,6 @@ int io_send_prep_async(struct io_kiocb *req) io = io_msg_alloc_async_prep(req); if (!io) return -ENOMEM; - io->free_iov = NULL; ret = move_addr_to_kernel(zc->addr, zc->addr_len, &io->addr); return ret; } @@ -209,7 +210,6 @@ static int io_setup_async_addr(struct io_kiocb *req, io = io_msg_alloc_async(req, issue_flags); if (!io) return -ENOMEM; - io->free_iov = NULL; memcpy(&io->addr, addr_storage, sizeof(io->addr)); return -EAGAIN; } @@ -479,7 +479,6 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, if (msg.msg_iovlen == 0) { sr->len = 0; - iomsg->free_iov = NULL; } else if (msg.msg_iovlen > 1) { return -EINVAL; } else { @@ -490,7 +489,6 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, if (clen < 0) return -EINVAL; sr->len = clen; - iomsg->free_iov = NULL; } if (req->flags & REQ_F_APOLL_MULTISHOT) { @@ -913,7 +911,9 @@ void io_send_zc_cleanup(struct io_kiocb *req) if (req_has_async_data(req)) { io = req->async_data; - kfree(io->free_iov); + /* might be ->fast_iov if *msg_copy_hdr failed */ + if (io->free_iov != io->fast_iov) + kfree(io->free_iov); } if (zc->notif) { zc->notif->flags |= REQ_F_CQE_SKIP; |