DEBIAN-CVE-2026-53385

Advisory lineage Upstream: 1 Downstream: 0
Upstream
Published: 19 Jul 2026, 12:16
Last modified:20 Jul 2026, 08:48

Vulnerability Summary

Overall Risk (default)
minimal
0/100
CVSS Score
No data
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

19 Jul 2026, 12:16
Published
Vulnerability first disclosed
20 Jul 2026, 08:48
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write A KASAN null-ptr-deref was observed in vcs_notifier(): BUG: KASAN: null-ptr-deref in vcs_notifier+0x98/0x130 Read of size 2 at addr qmp_cmd_name: qmp_capabilities, arguments: {} The issue is a race condition in vcs_write(). When the console_lock is temporarily dropped (to copy data from userspace), the vc_data pointer obtained from vcs_vc() may become stale. After re-acquiring the lock, vcs_vc() is called again to re-validate the pointer. If the vc has been deallocated in the meantime, vcs_vc() returns NULL, and the while loop breaks (with written > 0). However, after the loop, vcs_scr_updated(vc) is still called with the now-NULL vc pointer, leading to a null pointer dereference in the notifier chain (vcs_notifier dereferences param->vc). Fix this by adding a NULL check for vc before calling vcs_scr_updated().

Affected Systems

  • debianlinux

    all | < 6.1.177-1 | < 6.12.95-1 | < 7.0.14-1

References (1)