md/raid:md0: not clean -- starting background reconstruction md/raid:md0: device ram0 operational as raid disk 0 md/raid:md0: raid level 5 active with 1 out of 1 devices, algorithm 0 ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 shift exponent 64 is too large for 64-bit type 'unsigned long' CPU: 1 UID: 0 PID: 6948 Comm: syz.5.435 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 ubsan_epilogue+0x14/0x48 lib/ubsan.c:233 __ubsan_handle_shift_out_of_bounds+0x224/0x264 lib/ubsan.c:494 __roundup_pow_of_two include/linux/log2.h:57 [inline] raid5_set_limits+0x470/0x510 drivers/md/raid5.c:7835 raid5_run+0x1554/0x1b68 drivers/md/raid5.c:8133 md_run+0xb9c/0x1a6c drivers/md/md.c:6760 do_md_run+0x4c/0x4e4 drivers/md/md.c:6861 array_state_store+0x7a8/0xce8 drivers/md/md.c:-1 md_attr_store+0x304/0x438 drivers/md/md.c:6137 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x51c/0xa0c fs/read_write.c:687 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x84/0x98 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 ---[ end trace ]---