This is a note to let you know that I've just added the patch titled io_uring: fix {SQ,IO}POLL with unsupported opcodes to the 5.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-fix-sq-io-poll-with-unsupported-opcodes.patch and it can be found in the queue-5.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 63b7431c62d87074ff975d1d32dcd2915d679727 Author: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Wed Jun 3 18:03:22 2020 +0300 io_uring: fix {SQ,IO}POLL with unsupported opcodes [ Upstream commit 3232dd02af65f2d01be641120d2a710176b0c7a7 ] IORING_SETUP_IOPOLL is defined only for read/write, other opcodes should be disallowed, otherwise it'll get an error as below. Also refuse open/close with SQPOLL, as the polling thread wouldn't know which file table to use. RIP: 0010:io_iopoll_getevents+0x111/0x5a0 Call Trace: ? _raw_spin_unlock_irqrestore+0x24/0x40 ? do_send_sig_info+0x64/0x90 io_iopoll_reap_events.part.0+0x5e/0xa0 io_ring_ctx_wait_and_kill+0x132/0x1c0 io_uring_release+0x20/0x30 __fput+0xcd/0x230 ____fput+0xe/0x10 task_work_run+0x67/0xa0 do_exit+0x353/0xb10 ? handle_mm_fault+0xd4/0x200 ? syscall_trace_enter+0x18c/0x2c0 do_group_exit+0x43/0xa0 __x64_sys_exit_group+0x18/0x20 do_syscall_64+0x60/0x1e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> [axboe: allow provide/remove buffers and files update] Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/io_uring.c b/fs/io_uring.c index 4ab1728de247c..bb74e45941af2 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2748,6 +2748,8 @@ static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (req->flags & REQ_F_NEED_CLEANUP) return 0; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; sp->file_in = NULL; sp->off_in = READ_ONCE(sqe->splice_off_in); @@ -2910,6 +2912,8 @@ static int io_fallocate_prep(struct io_kiocb *req, { if (sqe->ioprio || sqe->buf_index || sqe->rw_flags) return -EINVAL; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; req->sync.off = READ_ONCE(sqe->off); req->sync.len = READ_ONCE(sqe->addr); @@ -2935,6 +2939,8 @@ static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) const char __user *fname; int ret; + if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + return -EINVAL; if (sqe->ioprio || sqe->buf_index) return -EINVAL; if (req->flags & REQ_F_FIXED_FILE) @@ -2968,6 +2974,8 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) size_t len; int ret; + if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + return -EINVAL; if (sqe->ioprio || sqe->buf_index) return -EINVAL; if (req->flags & REQ_F_FIXED_FILE) @@ -3207,6 +3215,8 @@ static int io_epoll_ctl_prep(struct io_kiocb *req, #if defined(CONFIG_EPOLL) if (sqe->ioprio || sqe->buf_index) return -EINVAL; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; req->epoll.epfd = READ_ONCE(sqe->fd); req->epoll.op = READ_ONCE(sqe->len); @@ -3251,6 +3261,8 @@ static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) if (sqe->ioprio || sqe->buf_index || sqe->off) return -EINVAL; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; req->madvise.addr = READ_ONCE(sqe->addr); req->madvise.len = READ_ONCE(sqe->len); @@ -3285,6 +3297,8 @@ static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { if (sqe->ioprio || sqe->buf_index || sqe->addr) return -EINVAL; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; req->fadvise.offset = READ_ONCE(sqe->off); req->fadvise.len = READ_ONCE(sqe->len); @@ -3322,6 +3336,8 @@ static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) unsigned lookup_flags; int ret; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; if (sqe->ioprio || sqe->buf_index) return -EINVAL; if (req->flags & REQ_F_FIXED_FILE) @@ -3402,6 +3418,8 @@ static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) */ req->work.flags |= IO_WQ_WORK_NO_CANCEL; + if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + return -EINVAL; if (sqe->ioprio || sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index) return -EINVAL;