In the Linux kernel, the following vulnerability has been resolved: zram: fix out-of-bounds access in writeback_store() Patch series "zram: fix… (CVE-2026-89718)
A vulnerability in the Linux kernel's zram component caused out-of-bounds memory access in the writeback_store() function due to inconsistent table scan bounds when the device is reset and reinitialized with a smaller disksize. The issue arises because the scan bounds were calculated before acquiring a lock, allowing the underlying table to change and leading to invalid memory access. The fix involves recalculating the scan bounds while holding the device lock to ensure consistency.
AI Analysis
Technical Summary
The Linux kernel's zram module had a vulnerability (CVE-2026-89718) where writeback_store() and read_block_state() functions derived their table scan bounds from zram->disksize before acquiring dev_lock. If the device was reset and reinitialized with a smaller disksize between reading the bounds and acquiring the lock, the scan bounds could reference the old table while the scan operated on the new one, causing out-of-bounds slot accesses. The patch moves the calculation of scan bounds under dev_lock to maintain consistency between the bounds and the table during scanning, preventing out-of-bounds memory access.
Potential Impact
This vulnerability could lead to out-of-bounds memory access in the Linux kernel's zram module, which may cause kernel crashes or memory corruption. The exact impact depends on the context in which the zram device is used. There are no known exploits in the wild.
Mitigation Recommendations
A patch has been released that fixes the vulnerability by recalculating the scan bounds while holding the device lock. Users should apply the official Linux kernel updates that include this fix. No additional mitigation steps are indicated.
In the Linux kernel, the following vulnerability has been resolved: zram: fix out-of-bounds access in writeback_store() Patch series "zram: fix… (CVE-2026-89718)
Description
A vulnerability in the Linux kernel's zram component caused out-of-bounds memory access in the writeback_store() function due to inconsistent table scan bounds when the device is reset and reinitialized with a smaller disksize. The issue arises because the scan bounds were calculated before acquiring a lock, allowing the underlying table to change and leading to invalid memory access. The fix involves recalculating the scan bounds while holding the device lock to ensure consistency.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel's zram module had a vulnerability (CVE-2026-89718) where writeback_store() and read_block_state() functions derived their table scan bounds from zram->disksize before acquiring dev_lock. If the device was reset and reinitialized with a smaller disksize between reading the bounds and acquiring the lock, the scan bounds could reference the old table while the scan operated on the new one, causing out-of-bounds slot accesses. The patch moves the calculation of scan bounds under dev_lock to maintain consistency between the bounds and the table during scanning, preventing out-of-bounds memory access.
Potential Impact
This vulnerability could lead to out-of-bounds memory access in the Linux kernel's zram module, which may cause kernel crashes or memory corruption. The exact impact depends on the context in which the zram device is used. There are no known exploits in the wild.
Mitigation Recommendations
A patch has been released that fixes the vulnerability by recalculating the scan bounds while holding the device lock. Users should apply the official Linux kernel updates that include this fix. No additional mitigation steps are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-8g3j-f4r3-9992
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89718"]
Threat ID: 6aa49fff55bf5e2cf5a865f6
Added to database: 09/12/2026, 00:42:39 UTC
Last enriched: 09/12/2026, 00:53:22 UTC
Last updated: 09/12/2026, 00:53:22 UTC
Views: 2
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.