media: af9005: Fix null-ptr-deref in af9005_i2c_xfer

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: media: af9005: Fix null-ptr-deref in af9005_i2c_xfer In af9005_i2c_xfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach af9005_i2c_xfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")

References

• https://git.kernel.org/stable/c/98c12abb275b75a98ff62de9466d21e4daa98536
• https://git.kernel.org/stable/c/63d962ac7a52c0ff4cd09af2e284dce5e5955dfe
• https://git.kernel.org/stable/c/0c02eb70b1dd4ae9bb304ce6cdadbc6faba2b2e9
• https://git.kernel.org/stable/c/c7e5ac737db25d7387fe517cb5207706782b6cf8
• https://git.kernel.org/stable/c/033b0c0780adee32dde218179e9bc51d2525108f
• https://git.kernel.org/stable/c/abb6fd93e05e80668d2317fe1110bc99b05034c3
• https://git.kernel.org/stable/c/e595ff350b2fd600823ee8491df7df693ae4b7c5
• https://git.kernel.org/stable/c/f4ee84f27625ce1fdf41e8483fa0561a1b837d10