Dear Linux folks,


On 12/13/17 14:13, Paul Menzel wrote:

> I enabled the undefined behavior sanitizer, and built Linus’ master 
> branch under Ubuntu 17.10 with gcc (Ubuntu 7.2.0-8ubuntu3) 7.2.0.
> 
> ```
> $ grep UBSAN /boot/config-4.15.0-rc3+
> CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y
> # CONFIG_ARCH_WANTS_UBSAN_NO_NULL is not set
> CONFIG_UBSAN=y
> CONFIG_UBSAN_SANITIZE_ALL=y
> # CONFIG_UBSAN_ALIGNMENT is not set
> CONFIG_UBSAN_NULL=y
> ```
> 
> Starting the system the messages below are printed.
> 
> ```
> [    0.758899] 
> ================================================================================ 
> 
> [    0.758960] UBSAN: Undefined behaviour in drivers/acpi/sysfs.c:849:33
> [    0.759008] shift exponent 64 is too large for 64-bit type 'long long unsigned int'
> [    0.759064] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc3+ #12
> [    0.759076] Hardware name: Notebook N24_25BU/N24_25BU, BIOS 5.12 07/07/2017
> [    0.759088] Call Trace:
> [    0.759118]  ? ftrace_graph_caller+0x98/0x98
> [    0.759133]  dump_stack+0x70/0xae
> [    0.759167]  ubsan_epilogue+0x9/0x40
> [    0.759188]  __ubsan_handle_shift_out_of_bounds+0x12b/0x170
> [    0.759214]  ? ftrace_graph_caller+0x68/0x98
> [    0.759293]  ? acpi_gpe_apply_masked_gpes+0x50/0xa9
> [    0.759314]  acpi_gpe_apply_masked_gpes+0x50/0xa9
> [    0.759348]  ? ftrace_graph_caller+0x98/0x98
> [    0.759363]  acpi_scan_init+0x145/0x2e4
> [    0.759385]  ? acpi_sleep_proc_init+0x24/0x24
> [    0.759413]  ? acpi_sleep_proc_init+0x24/0x24
> [    0.759429]  ? ftrace_graph_caller+0x98/0x98
> [    0.759444]  acpi_init+0x340/0x3a0
> [    0.759500]  ? ftrace_graph_caller+0x98/0x98
> [    0.759515]  do_one_initcall+0x173/0x200
> [    0.759553]  ? acpi_sleep_proc_init+0x24/0x24
> [    0.759573]  ? do_one_initcall+0x5/0x200
> [    0.759612]  ? ftrace_graph_caller+0x98/0x98
> [    0.759628]  kernel_init_freeable+0x305/0x395
> [    0.759653]  ? rest_init+0xd0/0xd0
> [    0.759689]  kernel_init+0xb/0x119
> [    0.759705]  ? rest_init+0xd0/0xd0
> [    0.759721]  ret_from_fork+0x1f/0x30
> [    0.759815] 
> ================================================================================ 
> 
> ```
> 
> Please tell me, if you need anything else to address this.

I created bug #198481 [1], so this is not forgotten about.


Kind regards,

Paul


[1] https://bugzilla.kernel.org/show_bug.cgi?id=198481