vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write
Summary
| CVE | CVE-2026-53385 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-19 12:16:49 UTC |
| Updated | 2026-07-19 12:16:49 UTC |
| 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(). |
Risk And Classification
EPSS: 0.001950000 probability, percentile 0.094660000 (date 2026-07-20)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 11dddfbb7a4e62489b01074d6c04d9d1b42e4047 43a6281790273c1b0a9ab76609ff0245b968f1e6 git | Not specified |
| CNA | Linux | Linux | affected e3d1adcad5b73c7ed0c7edb35ab68abcaa45cf67 b6bbb85cf45bf0b070e741997fe0af3a772c5ad5 git | Not specified |
| CNA | Linux | Linux | affected 3338d0b9acde770ee588eead5cac32c25e7048fc ff4806202749a51938236214adc0281481a57366 git | Not specified |
| CNA | Linux | Linux | affected 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 8232fca738011ca2ec865b46ec721d1796dc0580 git | Not specified |
| CNA | Linux | Linux | affected 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 73049768ad57145acd337102c5aa3c788e6642c8 git | Not specified |
| CNA | Linux | Linux | affected 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 7cc3dd79777f6ae4625ec37e84dd18a26dc88bde git | Not specified |
| CNA | Linux | Linux | affected 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 74be188eb2dc1c99d63986167b9a67d415fe7326 git | Not specified |
| CNA | Linux | Linux | affected 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 09a43e81279b8da15526da09877134b8bcf618b0 git | Not specified |
| CNA | Linux | Linux | affected 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 a287620312dc6dcb9a093417a0e589bf30fcf38a git | Not specified |
| CNA | Linux | Linux | affected 934de9a9b659785fed3e820bc0c813a460c71fea git | Not specified |
| CNA | Linux | Linux | affected 0deff678157333d775af190f84696336cdcccd6d git | Not specified |
| CNA | Linux | Linux | affected a4e3c4c65ae8510e01352c9a4347e05c035b2ce2 git | Not specified |
| CNA | Linux | Linux | affected 1de42e7653d6714a7507ba6696151a1fa028c69f git | Not specified |
| CNA | Linux | Linux | affected 5.10.181 5.10.260 semver | Not specified |
| CNA | Linux | Linux | affected 5.15.113 5.15.211 semver | Not specified |
| CNA | Linux | Linux | affected 6.1.30 6.1.177 semver | Not specified |
| CNA | Linux | Linux | affected 4.14.327 4.15 semver | Not specified |
| CNA | Linux | Linux | affected 4.19.284 4.20 semver | Not specified |
| CNA | Linux | Linux | affected 5.4.244 5.5 semver | Not specified |
| CNA | Linux | Linux | affected 6.3.4 6.4 semver | Not specified |
| CNA | Linux | Linux | affected 6.4 | Not specified |
| CNA | Linux | Linux | unaffected 6.4 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.260 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.211 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.177 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.144 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.95 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.37 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.14 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.2 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/74be188eb2dc1c99d63986167b9a67d415fe7326 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7cc3dd79777f6ae4625ec37e84dd18a26dc88bde | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/43a6281790273c1b0a9ab76609ff0245b968f1e6 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/73049768ad57145acd337102c5aa3c788e6642c8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ff4806202749a51938236214adc0281481a57366 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a287620312dc6dcb9a093417a0e589bf30fcf38a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b6bbb85cf45bf0b070e741997fe0af3a772c5ad5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/8232fca738011ca2ec865b46ec721d1796dc0580 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/09a43e81279b8da15526da09877134b8bcf618b0 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.