---
id: CVE-2026-53304
title: 'scsi: sg: Resolve soft lockup issue when opening /dev/sgX'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  scsi: sg: Resolve soft lockup issue when opening /dev/sgX

  The parameter def_reserved_size defines the default buffer size reserved
  for each Sg_fd and should be restric…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    3d74e0654ac908c65a8f20373091826fe43b1363
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    c47ccfb3d80dfed522ca06a5954ac97488d78c5a
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    fe671d3c84ffb1b763d590c25195755adeaadaba
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    c5f4a211e82d04ccc1809311322c47023bbe66e2
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    1afd963fcd963db0dc5d47df6dfcf010c9c4647e
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    feade299e932967de27519338d41de348fb5b061
  - >-
    Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a <
    d06a310b45e153872033dd0cf19d5a2279121099
  - Linux 2.6.19
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:26:08.178511Z'
published: '2026-06-26'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T16:34:19.492Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-53304'
references:
  - url: 'https://git.kernel.org/stable/c/3d74e0654ac908c65a8f20373091826fe43b1363'
  - url: 'https://git.kernel.org/stable/c/c47ccfb3d80dfed522ca06a5954ac97488d78c5a'
  - url: 'https://git.kernel.org/stable/c/fe671d3c84ffb1b763d590c25195755adeaadaba'
  - url: 'https://git.kernel.org/stable/c/c5f4a211e82d04ccc1809311322c47023bbe66e2'
  - url: 'https://git.kernel.org/stable/c/9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202'
  - url: 'https://git.kernel.org/stable/c/1afd963fcd963db0dc5d47df6dfcf010c9c4647e'
  - url: 'https://git.kernel.org/stable/c/feade299e932967de27519338d41de348fb5b061'
  - url: 'https://git.kernel.org/stable/c/d06a310b45e153872033dd0cf19d5a2279121099'
tags:
  - cve.org
epss: 0.00101
epssPercentile: 0.00885
ingestedAt: '2026-11-06T16:57:43.249Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

scsi: sg: Resolve soft lockup issue when opening /dev/sgX

The parameter def_reserved_size defines the default buffer size reserved
for each Sg_fd and should be restricted to a range between 0 and 1,048,576
(see https://tldp.org/HOWTO/SCSI-Generic-HOWTO/proc.html).  Although the
function sg_proc_write_dressz enforces this limit, it is possible to bypass
it by directly modifying the module parameter as shown below, which then
causes a soft lockup:

echo -1 > /sys/module/sg/parameters/def_reserved_size
exec 4<> /dev/sg0

watchdog: BUG: soft lockup - CPU#5 stuck for 26 seconds! [bash:537]
Modules loaded:
CPU: 5 UID: 0 PID: 537 Command: bash, kernel version 6.19.0-rc3+ #134,
PREEMPT disabled
Hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS version
1.16.1-2.fc37 dated 04/01/2014
...
Call Trace:

  sg_build_reserve+0x5c/0xa0
  sg_add_sfp+0x168/0x270
  sg_open+0x16e/0x340
  chrdev_open+0xbe/0x230
  do_dentry_open+0x175/0x480
  vfs_open+0x34/0xf0
  do_open+0x265/0x3d0
  path_openat+0x110/0x290
  do_filp_open+0xc3/0x170
  do_sys_openat2+0x71/0xe0
  __x64_sys_openat+0x6d/0xa0
  do_syscall_64+0x62/0x310
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

The fix is to use module_param_cb to validate and reject invalid values
assigned to def_reserved_size.

## Affected

- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < 3d74e0654ac908c65a8f20373091826fe43b1363`
- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < c47ccfb3d80dfed522ca06a5954ac97488d78c5a`
- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < fe671d3c84ffb1b763d590c25195755adeaadaba`
- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < c5f4a211e82d04ccc1809311322c47023bbe66e2`
- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < 9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202`
- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < 1afd963fcd963db0dc5d47df6dfcf010c9c4647e`
- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < feade299e932967de27519338d41de348fb5b061`
- `Linux >= 6460e75a104d10458817d2f5b2fbff775bf0b43a < d06a310b45e153872033dd0cf19d5a2279121099`
- `Linux 2.6.19`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.