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().
References
Configurations
Configuration 1 (hide)
|
History
29 Jul 2026, 19:31
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/09a43e81279b8da15526da09877134b8bcf618b0 - Patch | |
| References | () https://git.kernel.org/stable/c/43a6281790273c1b0a9ab76609ff0245b968f1e6 - Patch | |
| References | () https://git.kernel.org/stable/c/73049768ad57145acd337102c5aa3c788e6642c8 - Patch | |
| References | () https://git.kernel.org/stable/c/74be188eb2dc1c99d63986167b9a67d415fe7326 - Patch | |
| References | () https://git.kernel.org/stable/c/7cc3dd79777f6ae4625ec37e84dd18a26dc88bde - Patch | |
| References | () https://git.kernel.org/stable/c/8232fca738011ca2ec865b46ec721d1796dc0580 - Patch | |
| References | () https://git.kernel.org/stable/c/a287620312dc6dcb9a093417a0e589bf30fcf38a - Patch | |
| References | () https://git.kernel.org/stable/c/b6bbb85cf45bf0b070e741997fe0af3a772c5ad5 - Patch | |
| References | () https://git.kernel.org/stable/c/ff4806202749a51938236214adc0281481a57366 - Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| First Time |
Linux linux Kernel
Linux |
|
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.4:-:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.4:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.4:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.4:rc7:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.4:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.4:rc4:*:*:*:*:*:* |
|
| CWE | CWE-476 |
19 Jul 2026, 12:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-19 12:16
Updated : 2026-07-29 19:31
NVD link : CVE-2026-53385
Mitre link : CVE-2026-53385
CVE.ORG link : CVE-2026-53385
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-476
NULL Pointer Dereference