Detections
Analytics
Unity Linux 20.1070a Security Update: kernel (UTSA-2026-006985)
medium Nessus Plugin ID 308296
Synopsis
The Unity Linux host is missing one or more security updates.Description
The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-006985 advisory.In the Linux kernel, the following vulnerability has been resolved:
rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
Registering a kprobe on __rcu_irq_enter_check_tick() can cause kernel stack overflow as shown below. This issue can be reproduced by enabling CONFIG_NO_HZ_FULL and booting the kernel with argument nohz_full=, and then giving the following commands at the shell prompt:
# cd /sys/kernel/tracing/ # echo 'p:mp1 __rcu_irq_enter_check_tick' >> kprobe_events # echo 1 > events/kprobes/enable
This commit therefore adds __rcu_irq_enter_check_tick() to the kprobes blacklist using NOKPROBE_SYMBOL().
Insufficient stack space to handle exception! ESR: 0x00000000f2000004 -- BRK (AArch64) FAR: 0x0000ffffccf3e510 Task stack: [0xffff80000ad30000..0xffff80000ad38000] IRQ stack: [0xffff800008050000..0xffff800008058000] Overflow stack: [0xffff089c36f9f310..0xffff089c36fa0310] CPU: 5 PID: 190 Comm: bash Not tainted 6.2.0-rc2-00320-g1f5abbd77e2c #19 Hardware name: linux,dummy-virt (DT) pstate: 400003c5 (nZcv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __rcu_irq_enter_check_tick+0x0/0x1b8 lr : ct_nmi_enter+0x11c/0x138 sp : ffff80000ad30080 x29: ffff80000ad30080 x28: ffff089c82e20000 x27: 0000000000000000 x26: 0000000000000000 x25: ffff089c02a8d100 x24: 0000000000000000 x23: 00000000400003c5 x22: 0000ffffccf3e510 x21: ffff089c36fae148 x20: ffff80000ad30120 x19: ffffa8da8fcce148 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: ffffa8da8e44ea6c x14: ffffa8da8e44e968 x13: ffffa8da8e03136c x12: 1fffe113804d6809 x11: ffff6113804d6809 x10: 0000000000000a60 x9 : dfff800000000000 x8 : ffff089c026b404f x7 : 00009eec7fb297f7 x6 : 0000000000000001 x5 : ffff80000ad30120 x4 : dfff800000000000 x3 : ffffa8da8e3016f4 x2 : 0000000000000003 x1 : 0000000000000000 x0 : 0000000000000000 Kernel panic - not syncing: kernel stack overflow CPU: 5 PID: 190 Comm: bash Not tainted 6.2.0-rc2-00320-g1f5abbd77e2c #19 Hardware name: linux,dummy-virt (DT) Call trace:
dump_backtrace+0xf8/0x108 show_stack+0x20/0x30 dump_stack_lvl+0x68/0x84 dump_stack+0x1c/0x38 panic+0x214/0x404 add_taint+0x0/0xf8 panic_bad_stack+0x144/0x160 handle_bad_stack+0x38/0x58
__bad_stack+0x78/0x7c
__rcu_irq_enter_check_tick+0x0/0x1b8 arm64_enter_el1_dbg.isra.0+0x14/0x20 el1_dbg+0x2c/0x90 el1h_64_sync_handler+0xcc/0xe8 el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8 arm64_enter_el1_dbg.isra.0+0x14/0x20 el1_dbg+0x2c/0x90 el1h_64_sync_handler+0xcc/0xe8 el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8 arm64_enter_el1_dbg.isra.0+0x14/0x20 el1_dbg+0x2c/0x90 el1h_64_sync_handler+0xcc/0xe8 el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8 [...] el1_dbg+0x2c/0x90 el1h_64_sync_handler+0xcc/0xe8 el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8 arm64_enter_el1_dbg.isra.0+0x14/0x20 el1_dbg+0x2c/0x90 el1h_64_sync_handler+0xcc/0xe8 el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8 arm64_enter_el1_dbg.isra.0+0x14/0x20 el1_dbg+0x2c/0x90 el1h_64_sync_handler+0xcc/0xe8 el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8 el1_interrupt+0x28/0x60 el1h_64_irq_handler+0x18/0x28 el1h_64_irq+0x64/0x68
__ftrace_set_clr_event_nolock+0x98/0x198
__ftrace_set_clr_event+0x58/0x80 system_enable_write+0x144/0x178 vfs_write+0x174/0x738 ksys_write+0xd0/0x188
__arm64_sys_write+0x4c/0x60 invoke_syscall+0x64/0x180 el0_svc_common.constprop.0+0x84/0x160 do_el0_svc+0x48/0xe8 el0_svc+0x34/0xd0 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x190/0x194 SMP: stopping secondary CPUs Kernel Offset: 0x28da86000000 from 0xffff800008000000 PHYS_OFFSET: 0xfffff76600000000 CPU features: 0x00000,01a00100,0000421b Memory Limit: none
Tenable has extracted the preceding description block directly from the Unity Linux security advisory.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Solution
Update the affected kernel package.See Also
http://www.nessus.org/u?4a845c55
Plugin Details
Severity: Medium
ID: 308296
File Name: unity_linux_UTSA-2026-006985.nasl
Version: 1.1
Type: Local
Published: 4/21/2026
Updated: 4/21/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Medium
Base Score: 4.6
Temporal Score: 3.4
Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C
CVSS Score Source: CVE-2023-53655
CVSS v3
Risk Factor: Medium
Base Score: 5.5
Temporal Score: 4.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Required KB Items: Host/local_checks_enabled, Host/UOS-Server/release, Host/UOS-Server/rpm-list, Host/cpu
Exploit Ease: No known exploits are available
Patch Publication Date: 4/8/2026
Vulnerability Publication Date: 7/21/2021
Reference Information
CVE: CVE-2023-53655