This is a note to let you know that I've just added the patch titled io_uring: Replace 0-length array with flexible array to the 6.1-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-replace-0-length-array-with-flexible-array.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 36632d062975a9ff4410c90dd6d37922b68d0920 Mon Sep 17 00:00:00 2001 From: Kees Cook <keescook@xxxxxxxxxxxx> Date: Thu, 5 Jan 2023 11:05:11 -0800 Subject: io_uring: Replace 0-length array with flexible array From: Kees Cook <keescook@xxxxxxxxxxxx> commit 36632d062975a9ff4410c90dd6d37922b68d0920 upstream. Zero-length arrays are deprecated[1]. Replace struct io_uring_buf_ring's "bufs" with a flexible array member. (How is the size of this array verified?) Detected with GCC 13, using -fstrict-flex-arrays=3: In function 'io_ring_buffer_select', inlined from 'io_buffer_select' at io_uring/kbuf.c:183:10: io_uring/kbuf.c:141:23: warning: array subscript 255 is outside the bounds of an interior zero-length array 'struct io_uring_buf[0]' [-Wzero-length-bounds] 141 | buf = &br->bufs[head]; | ^~~~~~~~~~~~~~~ In file included from include/linux/io_uring.h:7, from io_uring/kbuf.c:10: include/uapi/linux/io_uring.h: In function 'io_buffer_select': include/uapi/linux/io_uring.h:628:41: note: while referencing 'bufs' 628 | struct io_uring_buf bufs[0]; | ^~~~ [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers") Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Pavel Begunkov <asml.silence@xxxxxxxxx> Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Cc: io-uring@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230105190507.gonna.131-kees@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/uapi/linux/io_uring.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -617,7 +617,7 @@ struct io_uring_buf_ring { __u16 resv3; __u16 tail; }; - struct io_uring_buf bufs[0]; + __DECLARE_FLEX_ARRAY(struct io_uring_buf, bufs); }; }; Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are queue-6.1/coda-avoid-partial-allocation-of-sig_inputargs.patch queue-6.1/bluetooth-hci_conn-refactor-hci_bind_bis-since-it-al.patch queue-6.1/regulator-s5m8767-bounds-check-id-indexing-into-arra.patch queue-6.1/gcc-plugins-drop-std-gnu-11-to-fix-gcc-13-build.patch queue-6.1/dmaengine-dw-axi-dmac-do-not-dereference-null-struct.patch queue-6.1/asoc-kirkwood-iterate-over-array-indexes-instead-of-.patch queue-6.1/fs-use-check_data_corruption-when-kernel-bugs-are-de.patch queue-6.1/crypto-hisilicon-wipe-entire-pool-on-error.patch queue-6.1/regulator-max77802-bounds-check-regulator-id-against.patch queue-6.1/io_uring-replace-0-length-array-with-flexible-array.patch queue-6.1/uaccess-add-minimum-bounds-check-on-kernel-buffer-si.patch queue-6.1/thermal-drivers-hisi-drop-second-sensor-hi3660.patch queue-6.1/scm-add-user-copy-checks-to-put_cmsg.patch queue-6.1/net-mlx4_en-introduce-flexible-array-to-silence-over.patch