Out-of-bounds read in Linux kernel - CVE-2026-98204

Vulnerability details

The vulnerability allows a local user to cause an out-of-bounds read.

The vulnerability exists due to incorrect block-length calculation in rmi_smb_write_block() when splitting writes into SMBus blocks. A local user can trigger a write with an input length greater than 32 bytes and a partial final block to cause an out-of-bounds read.

The final partial block causes smb_block_write() to read 32 bytes even when fewer bytes remain in the input buffer.

Affected software

How to mitigate CVE-2026-98204

External References

• https://git.kernel.org/stable/c/29fbcf5834f0a7f74bfd017c07da2411b35a4e2a
• https://git.kernel.org/stable/c/50dd585bee7669eb165e5defcc35d17f3822cfbb
• https://git.kernel.org/stable/c/51cfe54f815ae175c7d1126b983d4d7c89715004
• https://git.kernel.org/stable/c/7c800af1c6030a5f27d46ce7d6d5d75f9c1efaf8
• https://git.kernel.org/stable/c/9f0ce5e162eed8b68345abe839c59768bc60f99a
• https://git.kernel.org/stable/c/d01337c0892d1509500c727edf81380777c2dd0f
• https://git.kernel.org/stable/c/dc05ec97b8299e48e31367a9bc412c7e9c0e2b42
• https://git.kernel.org/stable/c/e022538e13dd1c82af5ec25ac28f12ca0ab26160

Related Security Bulletins

• Out-of-bounds read in Linux kernel input rmi4 driver
• Debian update for linux