CVE-2024-56769

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

media: dvb-frontends: dib3000mb: fix uninit-value in dib3000_write_reg

Syzbot reports [1] an uninitialized value issue found by KMSAN in

dib3000_read_reg().

Local u8 rb[2] is used in i2c_transfer() as a read buffer; in case

that call fails, the buffer may end up with some undefined values.

Since no elaborate error handling is expected in dib3000_write_reg(),

simply zero out rb buffer to mitigate the problem.

[1] Syzkaller report

dvb-usb: bulk message failed: -22 (6/0)

=====================================================

BUG: KMSAN: uninit-value in dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758

dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758

dibusb_dib3000mb_frontend_attach+0x155/0x2f0 drivers/media/usb/dvb-usb/dibusb-mb.c:31

dvb_usb_adapter_frontend_init+0xed/0x9a0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:290

dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References