CVE-2025-21767

Updated:

Description:

In the Linux kernel, the following vulnerability has been resolved: clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context The following bug report happened with a PREEMPT_RT kernel: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2012, name: kwatchdog preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 get_random_u32+0x4f/0x110 clocksource_verify_choose_cpus+0xab/0x1a0 clocksource_verify_percpu.part.0+0x6b/0x330 clocksource_watchdog_kthread+0x193/0x1a0 It is due to the fact that clocksource_verify_choose_cpus() is invoked with preemption disabled. This function invokes get_random_u32() to obtain random numbers for choosing CPUs. The batched_entropy_32 local lock and/or the base_crng.lock spinlock in driver/char/random.c will be acquired during the call. In PREEMPT_RT kernel, they are both sleeping locks and so cannot be acquired in atomic context. Fix this problem by using migrate_disable() to allow smp_processor_id() to be reliably used without introducing atomic context. preempt_disable() is then called after clocksource_verify_choose_cpus() but before the clocksource measurement is being run to avoid introducing unexpected latency. A vulnerability was found in the Linux kernel's clocksource subsystem, specifically affecting systems running with the PREEMPT_RT (Real-Time) patch. In real-time kernels, certain locks used within the random number generation functions, are implemented as sleeping locks. Calling these functions in an atomic context—where sleeping is not allowed—can lead to kernel warnings or crashes. The issue occurs when the get_random_u32() function is called within an atomic context, which is not permissible in real-time kernels due to the use of sleeping locks in the random number generation code.

CVSS3: 5.5


Vendor State

OS Vendor version Errata
Debian 11 5.10.237-1 DLA-4178-1
Ubuntu 22.04 5.15.0-140.150 USN-7510-1
Ubuntu 22.04 AWS 5.15.0-1084.91 USN-7510-7
Ubuntu 22.04 Azure 5.15.0-1089.98 USN-7510-3
Debian 11 cloud 5.10.237-1 DLA-4178-1
Ubuntu 20.04 HWE AWS 5.15.0-1084.91~20.04.1 USN-7510-8
Ubuntu 20.04 HWE Azure 5.15.0-1089.98~20.04.1 USN-7510-3
Amazon Linux 2023 6.1.129-138.220.amzn2023 ALAS2023-2025-876
Ubuntu 24.04 6.8.0-78.78 USN-7703-1
Ubuntu 24.04 AWS 6.8.0-1035.37 USN-7703-1

KernelCare State

OS Original kernel version State
Debian 11
Planned
Ubuntu 22.04
5.15.0-27.28 show all hide all
5.15.0-33.34 5.15.0-37.39 5.15.0-39.42 5.15.0-25.25 5.15.0-28.29 5.15.0-29.30 5.15.0-30.31 5.15.0-41.44 5.15.0-43.46 5.15.0-46.49 5.15.0-35.36 5.15.0-47.51 5.15.0-48.54 5.15.0-40.43 5.15.0-50.56 5.15.0-52.58 5.15.0-53.59 5.15.0-56.62 5.15.0-54.60 5.15.0-57.63 5.15.0-58.64 5.15.0-60.66 5.15.0-67.74 5.15.0-69.76 5.15.0-70.77 5.15.0-71.78 5.15.0-72.79 5.15.0-68.75 5.15.0-73.80 5.15.0-75.82 5.15.0-76.83 5.15.0-78.85 5.15.0-79.86 5.15.0-82.91 5.15.0-83.92 5.15.0-84.93 5.15.0-86.96 5.15.0-74.81 5.15.0-87.97 5.15.0-88.98 5.15.0-89.99 5.15.0-91.101 5.15.0-92.102 5.15.0-94.104 5.15.0-97.107 5.15.0-100.110 5.15.0-101.111 5.15.0-102.112 5.15.0-105.115 5.15.0-106.116 5.15.0-107.117 5.15.0-112.122 5.15.0-113.123 5.15.0-116.126 5.15.0-117.127 5.15.0-118.128 5.15.0-119.129 5.15.0-121.131 5.15.0-122.132 5.15.0-124.134 5.15.0-125.135 5.15.0-127.137 5.15.0-130.140 5.15.0-126.136 5.15.0-131.141 5.15.0-128.138 5.15.0-133.144 5.15.0-134.145 5.15.0-135.146 5.15.0-136.147 5.15.0-138.148 5.15.0-139.149
Released
Ubuntu 22.04 AWS
5.15.0-1005.7 show all hide all
5.15.0-1008.10 5.15.0-1011.14 5.15.0-1013.17 5.15.0-1015.19 5.15.0-1017.21 5.15.0-1009.11 5.15.0-1020.24 5.15.0-1021.25 5.15.0-1022.26 5.15.0-1023.27 5.15.0-1026.30 5.15.0-1004.6 5.15.0-1014.18 5.15.0-1018.22 5.15.0-1024.29 5.15.0-1027.31 5.15.0-1028.32 5.15.0-1030.34 5.15.0-1031.35 5.15.0-1033.37 5.15.0-1034.38 5.15.0-1035.39 5.15.0-1036.40 5.15.0-1032.36 5.15.0-1037.41 5.15.0-1038.43 5.15.0-1039.44 5.15.0-1040.45 5.15.0-1042.47 5.15.0-1043.48 5.15.0-1044.49 5.15.0-1045.50 5.15.0-1047.52 5.15.0-1048.53 5.15.0-1049.54 5.15.0-1050.55 5.15.0-1051.56 5.15.0-1052.57 5.15.0-1053.58 5.15.0-1055.60 5.15.0-1056.61 5.15.0-1057.63 5.15.0-1060.66 5.15.0-1061.67 5.15.0-1062.68 5.15.0-1063.69 5.15.0-1064.70 5.15.0-1065.71 5.15.0-1066.72 5.15.0-1067.73 5.15.0-1068.74 5.15.0-1069.75 5.15.0-1070.76 5.15.0-1071.77 5.15.0-1072.78 5.15.0-1073.79 5.15.0-1076.83 5.15.0-1078.85 5.15.0-1079.86 5.15.0-1080.87 5.15.0-1081.88 5.15.0-1082.89 5.15.0-1083.90
Released
Ubuntu 22.04 Azure
5.15.0-1005.6 show all hide all
5.15.0-1007.8 5.15.0-1010.12 5.15.0-1012.15 5.15.0-1014.17 5.15.0-1017.20 5.15.0-1008.9 5.15.0-1019.24 5.15.0-1020.25 5.15.0-1021.26 5.15.0-1022.27 5.15.0-1003.4 5.15.0-1013.16 5.15.0-1023.29 5.15.0-1029.36 5.15.0-1024.30 5.15.0-1034.41 5.15.0-1035.42 5.15.0-1036.43 5.15.0-1037.44 5.15.0-1038.45 5.15.0-1039.46 5.15.0-1040.47 5.15.0-1041.48 5.15.0-1042.49 5.15.0-1045.52 5.15.0-1046.53 5.15.0-1047.54 5.15.0-1049.56 5.15.0-1044.51 5.15.0-1050.57 5.15.0-1051.59 5.15.0-1052.60 5.15.0-1053.61 5.15.0-1054.62 5.15.0-1056.64 5.15.0-1057.65 5.15.0-1058.66 5.15.0-1059.67 5.15.0-1060.69 5.15.0-1061.70 5.15.0-1063.72 5.15.0-1064.73 5.15.0-1066.75 5.15.0-1067.76 5.15.0-1068.77 5.15.0-1070.79 5.15.0-1071.80 5.15.0-1072.81 5.15.0-1073.82 5.15.0-1074.83 5.15.0-1075.84 5.15.0-1078.87 5.15.0-1079.88 5.15.0-1081.90 5.15.0-1082.91 5.15.0-1084.93 5.15.0-1086.95 5.15.0-1087.96 5.15.0-1088.97
Released
Debian 11 cloud
Planned
Ubuntu 20.04 HWE AWS
5.15.0-1026.30~20.04.2 show all hide all
5.15.0-1022.26~20.04.1 5.15.0-1023.27~20.04.1 5.15.0-1021.25~20.04.1 5.15.0-1020.24~20.04.1 5.15.0-1017.21~20.04.1 5.15.0-1019.23~20.04.1 5.15.0-1014.18~20.04.1 5.15.0-1015.19~20.04.1 5.15.0-1018.22~20.04.1 5.15.0-1027.31~20.04.1 5.15.0-1028.32~20.04.1 5.15.0-1030.34~20.04.1 5.15.0-1031.35~20.04.1 5.15.0-1033.37~20.04.1 5.15.0-1034.38~20.04.1 5.15.0-1035.39~20.04.1 5.15.0-1036.40~20.04.1 5.15.0-1037.41~20.04.1 5.15.0-1038.43~20.04.1 5.15.0-1039.44~20.04.1 5.15.0-1040.45~20.04.1 5.15.0-1041.46~20.04.1 5.15.0-1043.48~20.04.1 5.15.0-1044.49~20.04.1 5.15.0-1045.50~20.04.1 5.15.0-1047.52~20.04.1 5.15.0-1048.53~20.04.1 5.15.0-1049.54~20.04.1 5.15.0-1050.55~20.04.1 5.15.0-1051.56~20.04.1 5.15.0-1052.57~20.04.1 5.15.0-1053.58~20.04.1 5.15.0-1055.60~20.04.1 5.15.0-1056.61~20.04.1 5.15.0-1057.63~20.04.1 5.15.0-1058.64~20.04.1 5.15.0-1061.67~20.04.1 5.15.0-1062.68~20.04.1 5.15.0-1063.69~20.04.1 5.15.0-1064.70~20.04.1 5.15.0-1065.71~20.04.1 5.15.0-1066.72~20.04.1 5.15.0-1067.73~20.04.1 5.15.0-1068.74~20.04.1 5.15.0-1069.75~20.04.1 5.15.0-1070.76~20.04.1 5.15.0-1071.77~20.04.1 5.15.0-1072.78~20.04.1 5.15.0-1073.79~20.04.1 5.15.0-1075.82~20.04.1 5.15.0-1077.84~20.04.1 5.15.0-1080.87~20.04.1 5.15.0-1081.88~20.04.1 5.15.0-1082.89~20.04.1 5.15.0-1083.90~20.04.1
Released
Ubuntu 20.04 HWE Azure
5.15.0-1029.36~20.04.1 show all hide all
5.15.0-1022.27~20.04.1 5.15.0-1023.29~20.04.1 5.15.0-1021.26~20.04.1 5.15.0-1020.25~20.04.1 5.15.0-1017.20~20.04.1 5.15.0-1019.24~20.04.1 5.15.0-1008.9~20.04.1 5.15.0-1013.16~20.04.1 5.15.0-1014.17~20.04.1 5.15.0-1024.30~20.04.1 5.15.0-1034.41~20.04.1 5.15.0-1049.56~20.04.1 5.15.0-1050.57~20.04.1 5.15.0-1054.62~20.04.1 5.15.0-1056.64~20.04.1 5.15.0-1057.65~20.04.1 5.15.0-1058.66~20.04.2 5.15.0-1059.67~20.04.1 5.15.0-1060.69~20.04.1 5.15.0-1061.70~20.04.1 5.15.0-1063.72~20.04.1 5.15.0-1064.73~20.04.1 5.15.0-1067.76~20.04.1 5.15.0-1068.77~20.04.1 5.15.0-1065.74~20.04.1 5.15.0-1070.79~20.04.1 5.15.0-1071.80~20.04.1 5.15.0-1072.81~20.04.1 5.15.0-1073.82~20.04.1 5.15.0-1074.83~20.04.1 5.15.0-1075.84~20.04.1 5.15.0-1078.87~20.04.1 5.15.0-1079.88~20.04.1 5.15.0-1081.90~20.04.1 5.15.0-1082.91~20.04.1 5.15.0-1086.95~20.04.1 5.15.0-1087.96~20.04.1 5.15.0-1088.97~20.04.1
Released
Debian 12
Planned
Amazon Linux 2023
Planned
Ubuntu 24.04
6.8.0-35.35 show all hide all
6.8.0-38.38 6.8.0-36.36 6.8.0-39.39 6.8.0-40.40 6.8.0-41.41 6.8.0-44.44 6.8.0-45.45 6.8.0-31.31 6.8.0-47.47 6.8.0-48.48 6.8.0-49.49 6.8.0-50.51 6.8.0-51.52 6.8.0-52.53 6.8.0-54.56 6.8.0-55.57 6.8.0-53.55 6.8.0-56.58 6.8.0-57.59 6.8.0-58.60 6.8.0-59.61 6.8.0-60.63 6.8.0-62.65 6.8.0-63.66 6.8.0-64.67 6.8.0-71.71
Released
Ubuntu 24.04 AWS
In Progress