OCTOBER 7, 2026
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Case File

CVE-2026-89847

CRITICAL · CVSS 9.8 EPSS 0.73%

Source: NVD + CISA KEV + EPSS · Published 2026-09-16 · Last synced 2026-10-07

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's SCSI subsystem, specifically the qla2xxx driver, where a use-after-free condition can occur due to improper handling of command completion in asynchronous I/O control block (IOCB) timeouts. This flaw can lead to potential system instability or exploitation, as it allows for double completion of commands, which could be leveraged by an attacker to execute arbitrary code or crash the system. Organizations utilizing affected Linux kernel versions, particularly those relying on the qla2xxx SCSI driver, should prioritize applying the relevant patches to mitigate this risk.

CVE
CVE-2026-89847
Severity
CRITICAL
CVSS
9.8
EPSS
0.73%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Avoid double completion in async IOCB timeout qla2x00_async_iocb_timeout() tries to abort a timed-out async IOCB. When qla24xx_async_abort_cmd() fails, both the SRB_LOGIN_CMD path and the SRB_CTRL_VP/default path scan outstanding_cmds[] for the SRB and then call sp->done(sp, QLA_FUNCTION_TIMEOUT) unconditionally, without checking whether the SRB was actually found and removed. If the response ISR completes the same handle first, it removes the SRB under qp_lock_ptr and runs sp->done() -> complete(sp->comp). The submitter qla24xx_control_vp() wakes from wait_for_completion(), clears sp->comp, drops its reference and returns, reclaiming the on-stack completion. The timer reference keeps the SRB alive across the timeout handler, but not the submitter's stack. The timeout then issues a second sp->done() -> qla_ctrlvp_sp_done(), which evaluates "if (sp->comp) complete(sp->comp)"; with the pointer loaded before the submitter's NULL store, complete() writes into the freed stack frame, a use-after-free. Track whether this path removed the SRB from outstanding_cmds and only call sp->done() when it did, so the command is completed exactly once by whichever path owns it. This mirrors the sp_found guard already used in qla24xx_abort_iocb_timeout().