CVE-2026-53304: Linux kernel · scsi: sg: Resolve soft lockup issue when opening /dev/sgX
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in feade299e932967de27519338d41de348fb5b061 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:49 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in feade299e932967de27519338d41de348fb5b061, fe671d3c84ffb1b763d590c25195755adeaadaba, d06a310b45e153872033dd0cf19d5a2279121099 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 26 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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.
References
- git.kernel.org/stable/c/3d74e0654ac908c65a8f20373091826fe43b1363 (opens in a new tab)
- git.kernel.org/stable/c/c47ccfb3d80dfed522ca06a5954ac97488d78c5a (opens in a new tab)
- git.kernel.org/stable/c/fe671d3c84ffb1b763d590c25195755adeaadaba (opens in a new tab)
- git.kernel.org/stable/c/c5f4a211e82d04ccc1809311322c47023bbe66e2 (opens in a new tab)
- git.kernel.org/stable/c/9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202 (opens in a new tab)
- git.kernel.org/stable/c/1afd963fcd963db0dc5d47df6dfcf010c9c4647e (opens in a new tab)
- git.kernel.org/stable/c/feade299e932967de27519338d41de348fb5b061 (opens in a new tab)
- git.kernel.org/stable/c/d06a310b45e153872033dd0cf19d5a2279121099 (opens in a new tab)