The test kernel fixes the problem. [ Test Plan ]
Installed 24.04. apt upgrade to install the latest kernel (6.8.0-136). Reboot with 6.8.0-136. Confirmed UBSAN warning messages (same as bug description). Installed lp_2161004_ubsan_array_index deb packages. Reboot with new kernel Confirmed no UBSAM warning messages. Kernel without the fix (July 1 build date): [ 0.000000] Linux version 6.8.0-136-generic (buildd@lcy02-amd64-041) (x86_64-linux-gnu-gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0, GNU ld (GNU Binutils for Ubuntu) 2.42) #136-Ubuntu SMP PREEMPT_DYNAMIC Wed Jul 1 21:53:05 UTC 2026 (Ubuntu 6.8.0-136.136-generic 6.8.12) Kernel with the fix (July 16 build date): [ 0.000000] Linux version 6.8.0-136-generic (root@buildnoble) (x86_64-linux-gnu-gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0, GNU ld (GNU Binutils for Ubuntu) 2.42) #136 SMP PREEMPT_DYNAMIC Thu Jul 16 20:05:25 UTC 2026 (Ubuntu 6.8.0-136.136-generic 6.8.12) [ Where problems could occur ] On boot, when running the UV initialization code (in x2apic_uv_x.c), right before the "UV: UVarchtype received from BIOS" message. Thanks -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2161004 Title: [SRU] HPE: Fix for UBSAN array-index-out-of-bounds To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161004/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
