CVE-2026-53304 is a vulnerability in Linux Kernel
Published on June 26, 2026
scsi: sg: Resolve soft lockup issue when opening /dev/sgX
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.
Products Associated with CVE-2026-53304
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Affected Versions
Linux:- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below 3d74e0654ac908c65a8f20373091826fe43b1363 is affected.
- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below c47ccfb3d80dfed522ca06a5954ac97488d78c5a is affected.
- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below fe671d3c84ffb1b763d590c25195755adeaadaba is affected.
- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below c5f4a211e82d04ccc1809311322c47023bbe66e2 is affected.
- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below 9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202 is affected.
- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below 1afd963fcd963db0dc5d47df6dfcf010c9c4647e is affected.
- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below feade299e932967de27519338d41de348fb5b061 is affected.
- Version 6460e75a104d10458817d2f5b2fbff775bf0b43a and below d06a310b45e153872033dd0cf19d5a2279121099 is affected.
- Version 2.6.19 is affected.
- Before 2.6.19 is unaffected.
- Version 5.10.258, <= 5.10.* is unaffected.
- Version 5.15.209, <= 5.15.* is unaffected.
- Version 6.1.175, <= 6.1.* is unaffected.
- Version 6.6.141, <= 6.6.* is unaffected.
- Version 6.12.91, <= 6.12.* is unaffected.
- Version 6.18.33, <= 6.18.* is unaffected.
- Version 7.0.10, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.