CVE-2026-72310smb: client: fix overflow in passthrough ioctl bounds check

Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix overflow in passthrough ioctl bounds check smb2_ioctl_query_info() validates the PASSTHRU_FSCTL response payload before copying it to userspace. The payload offset and length both come from 32-bit fields. The bounds check currently adds OutputOffset and qi.input_buffer_length directly, so the addition can wrap in 32-bit arithmetic before the result is compared against the response buffer length. A malicious server can use a large OutputOffset and a small OutputCount to make the wrapped sum pass the bounds check. The later copy_to_user() then reads from io_rsp + OutputOffset, outside the response buffer. Use size_add() for the offset plus length check so overflow is treated as out of bounds.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/175357ee0c596cb82054650dfa32fda51ad35aaa
• https://git.kernel.org/stable/c/dbd126539c098dba3159ce7d34b10b2daddcbd0f
• https://git.kernel.org/stable/c/63feb687e89a3a52a31e6e01764117cc500f1974
• https://git.kernel.org/stable/c/160045fc943f6c46b227644261252c8a22b8a87a
• https://git.kernel.org/stable/c/b30771b69eafae750afb7385fbcc3d77ed3f3670
• https://git.kernel.org/stable/c/1627e7d5c9b09721a141d07cedb178882f1ded67
• https://git.kernel.org/stable/c/1a638c55f2db6cb2296e5e3138015dd8fd9d4aa9
• https://git.kernel.org/stable/c/a4f27ad055392fa164f5649e89a3637b033c5fcc