Answer in brief
CVE-2026-23356 records a Unknown severity vulnerability in drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <933d161baa3794547adee621c0bf52cbf2c1b3cd || >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <cf01aa6288e1190f89865e765056e2a9d8190639 || >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <7752569fc78e89794ce28946529850282233f99d || >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <e91d8d6565b7819d13dab21d4dbed5b45efba59b || >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <eef1390125b660b8b61f9f227a03bb9c5e6d36a5 || >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <d1ef3aed4df2ef1fe46befd8f2da9a6ec5445508 || >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <f558e5404a72054b525dced1a0c66aa95a144153 || >=08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 <ab140365fb62c0bdab22b2f516aff563b2559e3b | 933d161baa3794547adee621c0bf52cbf2c1b3cd, cf01aa6288e1190f89865e765056e2a9d8190639, 7752569fc78e89794ce28946529850282233f99d, e91d8d6565b7819d13dab21d4dbed5b45efba59b, eef1390125b660b8b61f9f227a03bb9c5e6d36a5, d1ef3aed4df2ef1fe46befd8f2da9a6ec5445508, f558e5404a72054b525dced1a0c66aa95a144153, ab140365fb62c0bdab22b2f516aff563b2559e3b |
| Linux/Linuxgeneric | 3.10 | Not reported |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
Published upstream
Mar 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 15, 2026
In the Linux kernel, the following vulnerability has been resolved: drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock() Even though we check that we "should" be able to do lc_get_cumulative() while holding the device->al_lock spinlock, it may still fail, if some other code path decided to do lc_try_lock() with bad timing. If that happened, we logged "LOGIC BUG for enr=...", but still did not return an error. The rest of the code now assumed that this request has references for the relevant activity log extents. The implcations are that during an active resync, mutual exclusivity of resync versus application IO is not guaranteed. And a potential crash at this point may not realizs that these extents could have been target of in-flight IO and would need to be resynced just in case. Also, once the request completes, it will give up activity log references it does not even hold, which will trigger a BUG_ON(refcnt == 0) in lc_put(). Fix: Do not crash the kernel for a condition that is harmless during normal operation: also catch "e->refcnt == 0", not only "e == NULL" when being noisy about "al_complete_io() called on inactive extent %u\n". And do not try to be smart and "guess" whether something will work, then be surprised when it does not. Deal with the fact that it may or may not work. If it does not, remember a possible "partially in activity log" state (only possible for requests that cross extent boundaries), and return an error code from drbd_al_begin_io_nonblock(). A latter call for the same request will then resume from where we left off.
Quoted source text, attributed separately from HOL analysis.