Vulnerability record · CVE-2026-72310 · published 15 August 2026
CVE-2026-72310: In the Linux kernel, the following vulnerability has been resolved: smb: client: fix overflow in passthrough …
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.
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
References
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Source: NIST National Vulnerability Database (record CVE-2026-72310), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.
