Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Tue, 28 Dec 2021 08:47:15 +0100 | Subject | Re: KMSAN: uninit-value in alauda_check_media | From | Christophe JAILLET <> |
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Hi,
(2nd try - text only format - sorry for the noise)
first try to use syzbot. I hope I do it right. Discussion about the syz report can be found at https://lore.kernel.org/linux-kernel/0000000000007d25ff059457342d@google.com/
This patch only test if alauda_get_media_status() (and its embedded usb_stor_ctrl_transfer()) before using the data. In case of error, it returns USB_STOR_TRANSPORT_ERROR as done elsewhere.
#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
CJ
diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c index 20b857e97e60..6c486d964911 100644 --- a/drivers/usb/storage/alauda.c +++ b/drivers/usb/storage/alauda.c @@ -318,7 +318,8 @@ static int alauda_get_media_status(struct us_data *us, unsigned char *data) rc = usb_stor_ctrl_transfer(us, us->recv_ctrl_pipe, command, 0xc0, 0, 1, data, 2); - usb_stor_dbg(us, "Media status %02X %02X\n", data[0], data[1]); + if (rc == USB_STOR_XFER_GOOD) + usb_stor_dbg(us, "Media status %02X %02X\n", data[0], data[1]); return rc; } @@ -453,8 +454,11 @@ static int alauda_check_media(struct us_data *us) { struct alauda_info *info = (struct alauda_info *) us->extra; unsigned char status[2]; + int rc; - alauda_get_media_status(us, status); + rc = alauda_get_media_status(us, status); + if (rc != USB_STOR_TRANSPORT_GOOD) + return USB_STOR_TRANSPORT_ERROR; /* Check for no media or door open */ if ((status[0] & 0x80) || ((status[0] & 0x1F) == 0x10) | ![\](/images/icornerr.gif) |