Vulnerability Details CVE-2026-31652
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/stat: deallocate damon_call() failure leaking damon_ctx
damon_stat_start() always allocates the module's damon_ctx object
(damon_stat_context). Meanwhile, if damon_call() in the function fails,
the damon_ctx object is not deallocated. Hence, if the damon_call() is
failed, and the user writes Y to “enabled” again, the previously
allocated damon_ctx object is leaked.
This cannot simply be fixed by deallocating the damon_ctx object when
damon_call() fails. That's because damon_call() failure doesn't guarantee
the kdamond main function, which accesses the damon_ctx object, is
completely finished. In other words, if damon_stat_start() deallocates
the damon_ctx object after damon_call() failure, the not-yet-terminated
kdamond could access the freed memory (use-after-free).
Fix the leak while avoiding the use-after-free by keeping returning
damon_stat_start() without deallocating the damon_ctx object after
damon_call() failure, but deallocating it when the function is invoked
again and the kdamond is completely terminated. If the kdamond is not yet
terminated, simply return -EAGAIN, as the kdamond will soon be terminated.
The issue was discovered [1] by sashiko.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 4.1%
CVSS Severity
CVSS v3 Score 7.8
Products affected by CVE-2026-31652
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cpe:2.3:o:linux:linux_kernel:6.17
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cpe:2.3:o:linux:linux_kernel:6.17.1
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cpe:2.3:o:linux:linux_kernel:6.17.10
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cpe:2.3:o:linux:linux_kernel:6.17.11
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cpe:2.3:o:linux:linux_kernel:6.17.12
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cpe:2.3:o:linux:linux_kernel:6.17.13
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cpe:2.3:o:linux:linux_kernel:6.17.2
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cpe:2.3:o:linux:linux_kernel:6.17.3
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cpe:2.3:o:linux:linux_kernel:6.17.4
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cpe:2.3:o:linux:linux_kernel:6.17.5
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cpe:2.3:o:linux:linux_kernel:6.17.6
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cpe:2.3:o:linux:linux_kernel:6.17.7
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cpe:2.3:o:linux:linux_kernel:6.17.8
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cpe:2.3:o:linux:linux_kernel:6.17.9
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cpe:2.3:o:linux:linux_kernel:6.18
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cpe:2.3:o:linux:linux_kernel:6.18.1
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cpe:2.3:o:linux:linux_kernel:6.18.10
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cpe:2.3:o:linux:linux_kernel:6.18.11
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cpe:2.3:o:linux:linux_kernel:6.18.13
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cpe:2.3:o:linux:linux_kernel:6.18.14
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cpe:2.3:o:linux:linux_kernel:6.18.2
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cpe:2.3:o:linux:linux_kernel:6.18.3
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cpe:2.3:o:linux:linux_kernel:6.18.4
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cpe:2.3:o:linux:linux_kernel:6.18.5
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cpe:2.3:o:linux:linux_kernel:6.18.6
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cpe:2.3:o:linux:linux_kernel:6.18.7
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cpe:2.3:o:linux:linux_kernel:6.18.8
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cpe:2.3:o:linux:linux_kernel:6.18.9
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cpe:2.3:o:linux:linux_kernel:6.19
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cpe:2.3:o:linux:linux_kernel:6.19.1
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cpe:2.3:o:linux:linux_kernel:6.19.3
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cpe:2.3:o:linux:linux_kernel:6.19.4
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cpe:2.3:o:linux:linux_kernel:7.0