This is a note to let you know that I've just added the patch titled Input: iforce - invert valid length check when fetching device IDs to the 5.10-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: input-iforce-invert-valid-length-check-when-fetching-device-ids.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b8ebf250997c5fb253582f42bfe98673801ebebd Mon Sep 17 00:00:00 2001 From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Date: Mon, 7 Nov 2022 10:21:40 -0800 Subject: Input: iforce - invert valid length check when fetching device IDs From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> commit b8ebf250997c5fb253582f42bfe98673801ebebd upstream. syzbot is reporting uninitialized value at iforce_init_device() [1], for commit 6ac0aec6b0a6 ("Input: iforce - allow callers supply data buffer when fetching device IDs") is checking that valid length is shorter than bytes to read. Since iforce_get_id_packet() stores valid length when returning 0, the caller needs to check that valid length is longer than or equals to bytes to read. Reported-by: syzbot <syzbot+4dd880c1184280378821@xxxxxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Fixes: 6ac0aec6b0a6 ("Input: iforce - allow callers supply data buffer when fetching device IDs") Link: https://lore.kernel.org/r/531fb432-7396-ad37-ecba-3e42e7f56d5c@xxxxxxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/input/joystick/iforce/iforce-main.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/input/joystick/iforce/iforce-main.c +++ b/drivers/input/joystick/iforce/iforce-main.c @@ -273,22 +273,22 @@ int iforce_init_device(struct device *pa * Get device info. */ - if (!iforce_get_id_packet(iforce, 'M', buf, &len) || len < 3) + if (!iforce_get_id_packet(iforce, 'M', buf, &len) && len >= 3) input_dev->id.vendor = get_unaligned_le16(buf + 1); else dev_warn(&iforce->dev->dev, "Device does not respond to id packet M\n"); - if (!iforce_get_id_packet(iforce, 'P', buf, &len) || len < 3) + if (!iforce_get_id_packet(iforce, 'P', buf, &len) && len >= 3) input_dev->id.product = get_unaligned_le16(buf + 1); else dev_warn(&iforce->dev->dev, "Device does not respond to id packet P\n"); - if (!iforce_get_id_packet(iforce, 'B', buf, &len) || len < 3) + if (!iforce_get_id_packet(iforce, 'B', buf, &len) && len >= 3) iforce->device_memory.end = get_unaligned_le16(buf + 1); else dev_warn(&iforce->dev->dev, "Device does not respond to id packet B\n"); - if (!iforce_get_id_packet(iforce, 'N', buf, &len) || len < 2) + if (!iforce_get_id_packet(iforce, 'N', buf, &len) && len >= 2) ff_effects = buf[1]; else dev_warn(&iforce->dev->dev, "Device does not respond to id packet N\n"); Patches currently in stable-queue which might be from penguin-kernel@xxxxxxxxxxxxxxxxxxx are queue-5.10/input-iforce-invert-valid-length-check-when-fetching-device-ids.patch