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| author | Alviro Iskandar Setiawan <alviro.iskandar@gmail.com> | 2022-02-07 17:05:33 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-24 09:20:02 +0300 |
| commit | ddaaadf22bea31cf7e94d55c6530ce75947bb1cc (patch) | |
| tree | 53463ccfecdd8d7b4e042ab4675f8403791925e4 /io_uring | |
| parent | 8bc72b4952cf5ac6656ed718953c4d860fb69b15 (diff) | |
| download | linux-ddaaadf22bea31cf7e94d55c6530ce75947bb1cc.tar.xz | |
io_uring: Clean up a false-positive warning from GCC 9.3.0
commit 0d7c1153d9291197c1dc473cfaade77acb874b4b upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/io_uring.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index ac228efd5373..6852878e7762 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -5094,7 +5094,6 @@ 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; @@ -5109,6 +5108,7 @@ out_free: } req_set_fail(req); } else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) { +out_free: req_set_fail(req); } if (req->flags & REQ_F_BUFFER_SELECTED) |