The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Possible dependencies:
0d7c1153d929 ("io_uring: Clean up a false-positive warning from GCC 9.3.0") d1fd1c201d75 ("io_uring: simplify selected buf handling") 3648e5265cfa ("io_uring: move up io_put_kbuf() and io_put_rw_kbuf()") 04c76b41ca97 ("io_uring: add option to skip CQE posting") 913a571affed ("io_uring: clean cqe filling functions") 7297ce3d5944 ("io_uring: improve send/recv error handling") 54daa9b2d80a ("io_uring: correct fill events helpers types") 867f8fa5aeb7 ("io_uring: inline io_req_needs_clean()") d17e56eb4907 ("io_uring: remove struct io_completion") d886e185a128 ("io_uring: control ->async_data with a REQ_F flag") fff4e40e3094 ("io_uring: delay req queueing into compl-batch list") 51d48dab62ed ("io_uring: add more likely/unlikely() annotations") 7e3709d57651 ("io_uring: optimise kiocb layout") 30d51dd4ad20 ("io_uring: clean up buffer select") a1cdbb4cb5f7 ("io_uring: comment why inline complete calls io_clean_op()") ef05d9ebcc92 ("io_uring: kill off ->inflight_entry field") 6962980947e2 ("io_uring: restructure submit sqes to_submit checks") d9f9d2842c91 ("io_uring: reshuffle queue_sqe completion handling") f5ed3bcd5b11 ("io_uring: optimise batch completion") b3fa03fd1b17 ("io_uring: convert iopoll_completed to store_release")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0d7c1153d9291197c1dc473cfaade77acb874b4b Mon Sep 17 00:00:00 2001 From: Alviro Iskandar Setiawan alviro.iskandar@gmail.com Date: Mon, 7 Feb 2022 21:05:33 +0700 Subject: [PATCH] io_uring: Clean up a false-positive warning from GCC 9.3.0
In io_recv(), if import_single_range() fails, the @flags variable is uninitialized, then it will goto out_free.
After the goto, the compiler doesn't know that (ret < min_ret) is always true, so it thinks the "if ((flags & MSG_WAITALL) ..." path could be taken.
The complaint comes from gcc-9 (Debian 9.3.0-22) 9.3.0: ``` fs/io_uring.c:5238 io_recvfrom() error: uninitialized symbol 'flags' ``` Fix this by bypassing the @ret and @flags check when import_single_range() fails.
Reasons: 1. import_single_range() only returns -EFAULT when it fails. 2. At that point, @flags is uninitialized and shouldn't be read.
Reported-by: kernel test robot lkp@intel.com Reported-by: Dan Carpenter dan.carpenter@oracle.com Reported-by: "Chen, Rong A" rong.a.chen@intel.com Link: https://lore.gnuweeb.org/timl/d33bb5a9-8173-f65b-f653-51fc0681c6d6@intel.com... Cc: Pavel Begunkov asml.silence@gmail.com Suggested-by: Ammar Faizi ammarfaizi2@gnuweeb.org Fixes: 7297ce3d59449de49d3c9e1f64ae25488750a1fc ("io_uring: improve send/recv error handling") Signed-off-by: Alviro Iskandar Setiawan alviro.iskandar@gmail.com Signed-off-by: Ammar Faizi ammarfaizi2@gnuweeb.org Link: https://lore.kernel.org/r/20220207140533.565411-1-ammarfaizi2@gnuweeb.org Signed-off-by: Jens Axboe axboe@kernel.dk
diff --git a/fs/io_uring.c b/fs/io_uring.c index 2e04f718319d..3445c4da0153 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5228,7 +5228,6 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) min_ret = iov_iter_count(&msg.msg_iter);
ret = sock_recvmsg(sock, &msg, flags); -out_free: if (ret < min_ret) { if (ret == -EAGAIN && force_nonblock) return -EAGAIN; @@ -5236,9 +5235,9 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) ret = -EINTR; req_set_fail(req); } else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) { +out_free: req_set_fail(req); } - __io_req_complete(req, issue_flags, ret, io_put_kbuf(req)); return 0; }