Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-08-15T00:00:00 kernel: smb: client: fix overflow in passthrough ioctl bounds check 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CWE-125

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.

A flaw was found in the Linux kernel's Server Message Block (SMB) client. A malicious SMB server could exploit an integer overflow vulnerability in the `smb2_ioctl_query_info()` function's bounds check. By sending a specially crafted response with a large offset, the server can cause the client to read data beyond the allocated buffer. This out-of-bounds read could lead to information disclosure from the kernel memory.

Red Hat Enterprise Linux 10 Affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Affected kernel Red Hat Enterprise Linux 8 Affected kernel-rt Red Hat Enterprise Linux 9 Affected kernel Red Hat Enterprise Linux 9 Affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-72310 https://nvd.nist.gov/vuln/detail/CVE-2026-72310 https://lore.kernel.org/linux-cve-announce/2026081504-CVE-2026-72310-7e47@gregkh/T