UBUNTU-CVE-2025-39833: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: mISDN: hfcpci: Fix warning when deleting uninitialized timer With CONFIGDEBUGOBJECTSTIMERS unloading hfcpci module leads to the following splat: [ 250.215892] ODEBUG: assertinit not available (active state 0) object: ffffffffc01a3dc0 object type: timerlist hint: 0x0 [ 250.217520] WARNING: CPU: 0 PID: 233 at lib/debugobjects.c:612 debugprintobject+0x1b6/0x2c0 [ 250.218775] Modules linked in: hfcpci(-) mISDNcore [ 250.219537] CPU: 0 UID: 0 PID: 233 Comm: rmmod Not tainted 6.17.0-rc2-g6f713187ac98 #2 PREEMPT(voluntary) [ 250.220940] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 250.222377] RIP: 0010:debugprintobject+0x1b6/0x2c0 [ 250.223131] Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4f 41 56 48 8b 14 dd a0 4e 01 9f 48 89 ee 48 c7 c7 20 46 01 9f e8 cb 84d [ 250.225805] RSP: 0018:ffff888015ea7c08 EFLAGS: 00010286 [ 250.226608] RAX: 0000000000000000 RBX: 0000000000000005 RCX: ffffffff9be93a95 [ 250.227708] RDX: 1ffff1100d945138 RSI: 0000000000000008 RDI: ffff88806ca289c0 [ 250.228993] RBP: ffffffff9f014a00 R08: 0000000000000001 R09: ffffed1002bd4f39 [ 250.230043] R10: ffff888015ea79cf R11: 0000000000000001 R12: 0000000000000001 [ 250.231185] R13: ffffffff9eea0520 R14: 0000000000000000 R15: ffff888015ea7cc8 [ 250.232454] FS: 00007f3208f01540(0000) GS:ffff8880caf5a000(0000) knlGS:0000000000000000 [ 250.233851] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 250.234856] CR2: 00007f32090a7421 CR3: 0000000004d63000 CR4: 00000000000006f0 [ 250.236117] Call Trace: [ 250.236599] <TASK> [ 250.236967] ? traceirqenable.constprop.0+0xd4/0x130 [ 250.237920] debugobjectassertinit+0x1f6/0x310 [ 250.238762] ? pfxdebugobjectassertinit+0x10/0x10 [ 250.239658] ? lockacquire+0xdea/0x1c70 [ 250.240369] trytodeltimersync+0x69/0x140 [ 250.241172] ? pfxtrytodeltimersync+0x10/0x10 [ 250.242058] ? timerdeletesync+0xc6/0x120 [ 250.242842] ? lockacquire+0x30/0x80 [ 250.243474] ? timerdeletesync+0xc6/0x120 [ 250.244262] timerdeletesync+0x98/0x120 [ 250.245015] HFCcleanup+0x10/0x20 [hfcpci] [ 250.245704] dosysdeletemodule+0x348/0x510 [ 250.246461] ? pfxdosysdeletemodule+0x10/0x10 [ 250.247338] dosyscall64+0xc1/0x360 [ 250.247924] entrySYSCALL64afterhwframe+0x77/0x7f Fix this by initializing hfctl timer with DEFINETIMER macro. Also, use modtimer instead of manual timeout update.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1069.74~22.04.1 - Upgrade
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ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1073.82~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1071.78~22.04.1 - Upgrade
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ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1073.81~22.04.1 - Upgrade
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ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1069.70~22.04.1 - Upgrade
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ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-149.149.1~22.04.1 - Upgrade
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ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1067.71~22.04.1 - Upgrade
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ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1064.65~22.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-149.149 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1069.74 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1073.82 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1073.81 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1068.77 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1053.57 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1069.70 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-149.149.1 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1067.70 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1067.71 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1068.72 - Upgrade
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ubuntu/linux-vmwareto a version that resolves this vulnerability.Fixed in 6.8.0-1010.10 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1036.41 - Upgrade
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ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2056.58 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1064.65 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1069.74+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1073.82+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1073.81+fips1 - Compensating control
Initialize the mISDN hfcpci hfc_tl timer with the DEFINE_TIMER macro.
- Compensating control
Use mod_timer instead of manually updating the timeout.
Event History
Frequently Asked Questions
Who would need access to exploit this issue?
The CVSS vector indicates local access and low privileges are required. No user interaction is required.
Which Ubuntu kernel package families are listed as affected?
The listed software includes ubuntu/linux, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-gcp, and their corresponding FIPS variants: linux-fips, linux-aws-fips, linux-azure-fips, and linux-gcp-fips.
How can I identify the reported failure condition?
The reported symptom occurs when unloading the hfcpci module with CONFIG_DEBUG_OBJECTS_TIMERS enabled. Logs show an ODEBUG "assert_init not available" message for a timer_list and a warning from debug_print_object while rmmod is running.