media: dw2102: Fix null-ptr-deref in dw2102_i2c_transfer()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: media: dw2102: Fix null-ptr-deref in dw2102_i2c_transfer() In dw2102_i2c_transfer, 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 dw2102_i2c_transfer. 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 950e252cb469 ("[media] dw2102: limit messages to buffer size")

References

• https://git.kernel.org/stable/c/77cbd42d29de9ffc93d5529bab8813cde53af14c
• https://git.kernel.org/stable/c/ecbe6d011b95c7da59f014f8d26cb7245ed1e11e
• https://git.kernel.org/stable/c/beb9550494e7349f92b9eaa283256a5ad9b1c9be
• https://git.kernel.org/stable/c/97fdbdb750342cbc204befde976872fedb406ee6
• https://git.kernel.org/stable/c/903566208ae6bb9c0e7e54355ce75bf6cf72485d
• https://git.kernel.org/stable/c/08dfcbd03b2b7f918c4f87c6ff637054e510df74
• https://git.kernel.org/stable/c/fb28afab113a82b89ffec48c8155ec05b4f8cb5e
• https://git.kernel.org/stable/c/5ae544d94abc8ff77b1b9bf8774def3fa5689b5b