[Bug 2161004] Re: [SRU] HPE: Fix for UBSAN array-index-out-of-bounds

** Changed in: linux (Ubuntu Noble) Status: In Progress => Fix Committed -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161004 Title: [SRU] HPE: Fix for UBSAN array-index-out-of-bounds Status in linux package in Ubuntu: Fix Committed Status in linux source package in Noble: Fix Committed Status in linux source package in Resolute: Fix Committed Status in linux source package in Stonking: Fix Committed Bug description: [ Impact ] When UBSAN is enabled, multiple array-index-out-of-bounds messages are printed:   [ 0.000000] [ T0] UBSAN: array-index-out-of-bounds in arch/x86/kernel/apic/x2apic_uv_x.c:276:23   [ 0.000000] [ T0] index 1 is out of range for type '<unknown> [1]'   ...   [ 0.000000] [ T0] UBSAN: array-index-out-of-bounds in arch/x86/kernel/apic/x2apic_uv_x.c:277:32   [ 0.000000] [ T0] index 1 is out of range for type '<unknown> [1]'   ...   [ 0.000000] [ T0] UBSAN: array-index-out-of-bounds in arch/x86/kernel/apic/x2apic_uv_x.c:282:16   [ 0.000000] [ T0] index 1 is out of range for type '<unknown> [1]'   ...   [ 0.515850] [ T1] UBSAN: array-index-out-of-bounds in arch/x86/kernel/apic/x2apic_uv_x.c:1344:23   [ 0.519851] [ T1] index 1 is out of range for type '<unknown> [1]'   ...   [ 0.603850] [ T1] UBSAN: array-index-out-of-bounds in arch/x86/kernel/apic/x2apic_uv_x.c:1345:32   [ 0.607850] [ T1] index 1 is out of range for type '<unknown> [1]'   ...   [ 0.691850] [ T1] UBSAN: array-index-out-of-bounds in arch/x86/kernel/apic/x2apic_uv_x.c:1353:20   [ 0.695850] [ T1] index 1 is out of range for type '<unknown> [1]' One-element arrays have been deprecated: [ Fix ] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=21433d3e3ca14d20f9b0c2237b3d3a1355af7907 [ 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 ] The regression risk is low [ Other Info ] https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/noble/+ref/ubsan_array_index To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161004/+subscriptions