Answer in brief
CVE-2025-39737 records a Medium severity (CVSS 5.5) vulnerability in mm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC CN 4100 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. 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 CN 4100 (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.4:-:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.4:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.4:rc5:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.4:rc6:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.4:rc7:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.4:rc8:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <9f1f4e95031f84867c5821540466d62f88dab8ca || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <1ef72a7fedc5bca70e8cc980985790de10d407aa || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <a04de4c40aab9b338dfa989cf4aec70fd187eeb2 || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <f014c10d190b92aad366e56b445daffcd1c075e4 || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <e21a3ddd58733ce31afcb1e5dc3cb80a4b5bc29b || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <8d2d22a55ffe35c38e69795468a7addd1a80e9ce || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <926092268efdf1ed7b55cf486356c74a9e7710d1 || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <9b80430c194e4a114dc663c1025d56b4f3d0153d || >=2abd839aa7e615f2bbc50c8ba7deb9e40d186768 <d1534ae23c2b6be350c8ab060803fbf6e9682adc | 9f1f4e95031f84867c5821540466d62f88dab8ca, 1ef72a7fedc5bca70e8cc980985790de10d407aa, a04de4c40aab9b338dfa989cf4aec70fd187eeb2, f014c10d190b92aad366e56b445daffcd1c075e4, e21a3ddd58733ce31afcb1e5dc3cb80a4b5bc29b, 8d2d22a55ffe35c38e69795468a7addd1a80e9ce, 926092268efdf1ed7b55cf486356c74a9e7710d1, 9b80430c194e4a114dc663c1025d56b4f3d0153d, d1534ae23c2b6be350c8ab060803fbf6e9682adc |
| Linux/Linuxgeneric | 5.4 | Not reported |
| Siemens/SIMATIC CN 4100generic | >=0 <V5.0 | V5.0 |
Published upstream
Sep 11, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
In the Linux kernel, the following vulnerability has been resolved: mm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup() A soft lockup warning was observed on a relative small system x86-64 system with 16 GB of memory when running a debug kernel with kmemleak enabled. watchdog: BUG: soft lockup - CPU#8 stuck for 33s! [kworker/8:1:134] The test system was running a workload with hot unplug happening in parallel. Then kemleak decided to disable itself due to its inability to allocate more kmemleak objects. The debug kernel has its CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE set to 40,000. The soft lockup happened in kmemleak_do_cleanup() when the existing kmemleak objects were being removed and deleted one-by-one in a loop via a workqueue. In this particular case, there are at least 40,000 objects that need to be processed and given the slowness of a debug kernel and the fact that a raw_spinlock has to be acquired and released in __delete_object(), it could take a while to properly handle all these objects. As kmemleak has been disabled in this case, the object removal and deletion process can be further optimized as locking isn't really needed. However, it is probably not worth the effort to optimize for such an edge case that should rarely happen. So the simple solution is to call cond_resched() at periodic interval in the iteration loop to avoid soft lockup.
Quoted source text, attributed separately from HOL analysis.