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

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-usb-init.c:90 [inline] dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:186 [inline] dvb_usb_device_init+0x25a8/0x3760 drivers/media/usb/dvb-usb/dvb-usb-init.c:310 dibusb_probe+0x46/0x250 drivers/media/usb/dvb-usb/dibusb-mb.c:110 ... Local variable rb created at: dib3000_read_reg+0x86/0x4e0 drivers/media/dvb-frontends/dib3000mb.c:54 dib3000mb_attach+0x123/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758 ...

N/A

N/A

Linux kernel 安全漏洞

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于在media模块的dvb-frontends/dib3000mb驱动中，dib3000_read_reg函数中使用了未初始化的局部变量rb作为读缓冲区，当i2c_transfer调用失败时，缓冲区可能包含未定义值，进而导致dib3000mb_attach函数中出现KMSAN报告的uninit-value错误，影响设备的正常工作和数据传输的可靠性。

N/A

N/A