CVE-2026-53304

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

MEDIUM

5.5

CVSS Score

Published: June 26, 2026 at 07:41 PM UTC

Updated: July 6, 2026 at 08:43 PM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.1%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

2.6.19 ≤ v < 5.10.2582.6.19 ≤ v < 5.15.2092.6.19 ≤ v < 6.1.1752.6.19 ≤ v < 6.12.912.6.19 ≤ v < 6.18.332.6.19 ≤ v < 6.6.1412.6.19 ≤ v < 7.0.102.6.19 ≤ v < 7.15.11 ≤ v < 5.15.2095.16 ≤ v < 6.1.1756.13 ≤ v < 6.18.336.19 ≤ v < 7.0.106.2 ≤ v < 6.6.1416.7 ≤ v < 6.12.912.6.196460e75a104d10458817d2f5b2fbff775bf0b43a

Vendor states this is fixed in 1afd963fcd963db0dc5d47df6dfcf010c9c4647e (fixed)

Vendor states this is fixed in 3d74e0654ac908c65a8f20373091826fe43b1363 (fixed)

Vendor states this is fixed in 9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202 (fixed)

Vendor states this is fixed in c47ccfb3d80dfed522ca06a5954ac97488d78c5a (fixed)

Vendor states this is fixed in c5f4a211e82d04ccc1809311322c47023bbe66e2 (fixed)

Vendor states this is fixed in d06a310b45e153872033dd0cf19d5a2279121099 (fixed)

Vendor states this is fixed in fe671d3c84ffb1b763d590c25195755adeaadaba (fixed)

Vendor states this is fixed in feade299e932967de27519338d41de348fb5b061 (fixed)

Vendor states this is fixed in 2.6.19 (unaffected)

Vendor states this is fixed in 5.10.258 (unaffected)

Vendor states this is fixed in 5.15.209 (unaffected)

Vendor states this is fixed in 6.1.175 (unaffected)