CVE-2025-39900

{"id": "CVE-2025-39900", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-39900", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-01-14T19:29:22.173838Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "d2d6422f8bd17c6bb205133e290625a564194496", "lessThan": "a22ec2ee824be30803068a52f78f7ffe3bc879fb", "versionType": "git"}, {"status": "affected", "version": "d2d6422f8bd17c6bb205133e290625a564194496", "lessThan": "e79923824c48b930609680be04cb29253fc4a17d", "versionType": "git"}, {"status": "affected", "version": "d2d6422f8bd17c6bb205133e290625a564194496", "lessThan": "9f74c0ea9b26d1505d55b61e36b1623dd347e1d1", "versionType": "git"}], "programFiles": ["net/core/gen_estimator.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.12"}, {"status": "unaffected", "version": "0", "lessThan": "6.12", "versionType": "semver"}, {"status": "unaffected", "version": "6.12.46", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.16.6", "versionType": "semver", "lessThanOrEqual": "6.16.*"}, {"status": "unaffected", "version": "6.17", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/core/gen_estimator.c"], "defaultStatus": "affected"}]}], "published": "2025-10-01T08:15:32.740", "references": [{"url": "https://git.kernel.org/stable/c/9f74c0ea9b26d1505d55b61e36b1623dd347e1d1", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a22ec2ee824be30803068a52f78f7ffe3bc879fb", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e79923824c48b930609680be04cb29253fc4a17d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: gen_estimator: fix est_timer() vs CONFIG_PREEMPT_RT=y\n\nsyzbot reported a WARNING in est_timer() [1]\n\nProblem here is that with CONFIG_PREEMPT_RT=y, timer callbacks\ncan be preempted.\n\nAdopt preempt_disable_nested()/preempt_enable_nested() to fix this.\n\n[1]\n WARNING: CPU: 0 PID: 16 at ./include/linux/seqlock.h:221 __seqprop_assert include/linux/seqlock.h:221 [inline]\n WARNING: CPU: 0 PID: 16 at ./include/linux/seqlock.h:221 est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93\nModules linked in:\nCPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025\n RIP: 0010:__seqprop_assert include/linux/seqlock.h:221 [inline]\n RIP: 0010:est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93\nCall Trace:\n <TASK>\n call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747\n expire_timers kernel/time/timer.c:1798 [inline]\n __run_timers kernel/time/timer.c:2372 [inline]\n __run_timer_base+0x648/0x970 kernel/time/timer.c:2384\n run_timer_base kernel/time/timer.c:2393 [inline]\n run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403\n handle_softirqs+0x22c/0x710 kernel/softirq.c:579\n __do_softirq kernel/softirq.c:613 [inline]\n run_ktimerd+0xcf/0x190 kernel/softirq.c:1043\n smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160\n kthread+0x70e/0x8a0 kernel/kthread.c:463\n ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n </TASK>"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet_sched: gen_estimator: correcci\u00f3n de est_timer() frente a CONFIG_PREEMPT_RT=y\n\nsyzbot inform\u00f3 una ADVERTENCIA en est_timer() [1]\n\nEl problema aqu\u00ed es que con CONFIG_PREEMPT_RT=y, las devoluciones de llamada del temporizador pueden ser expropiadas.\n\nSe adoptan preempt_disable_nested()/preempt_enable_nested() para solucionar esto.\n\n[1]\n ADVERTENCIA: CPU: 0 PID: 16 en ./include/linux/seqlock.h:221 __seqprop_assert include/linux/seqlock.h:221 [en l\u00ednea]\n ADVERTENCIA: CPU: 0 PID: 16 en ./include/linux/seqlock.h:221 est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93\nM\u00f3dulos enlazados:\nCPU: 0 UID: 0 PID: 16 Comm: ktimers/0 No contaminado syzkaller #0 PREEMPT_{RT,(full)}\nNombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025\n RIP: 0010:__seqprop_assert include/linux/seqlock.h:221 [en l\u00ednea]\n RIP: 0010:est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93\nTraza de llamadas:\n <TAREA>\n call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747\n expire_timers kernel/time/timer.c:1798 [en l\u00ednea]\n __run_timers kernel/time/timer.c:2372 [en l\u00ednea]\n __run_timer_base+0x648/0x970 kernel/time/timer.c:2384\n run_timer_base kernel/time/timer.c:2393 [en l\u00ednea]\n run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403\n handle_softirqs+0x22c/0x710 kernel/softirq.c:579\n __do_softirq kernel/softirq.c:613 [en l\u00ednea]\n run_ktimerd+0xcf/0x190 kernel/softirq.c:1043\n smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160\n kthread+0x70e/0x8a0 kernel/kthread.c:463\n ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n </TAREA>"}], "lastModified": "2026-10-19T21:10:00.160", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "96546B77-B366-48B1-AAAE-0BD3C9328ECC", "versionEndExcluding": "6.12.46", "versionStartIncluding": "6.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "548F104C-0F08-438B-9C97-64C903F0C678", "versionEndExcluding": "6.16.6", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C730CD9A-D969-4A8E-9522-162AAF7C0EE9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "39982C4B-716E-4B2F-8196-FA301F47807D"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "340BEEA9-D70D-4290-B502-FBB1032353B1"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}