[kees:devel/overflow/sanitizers] [overflow] 660787b56e: UBSAN:signed-integer-overflow_in_lib/test_memcat_p.c

[kernel test robot]

Hello,

kernel test robot noticed "UBSAN:signed-integer-overflow_in_lib/test_memcat_p.c" on:

commit: 660787b56e6e97ddc34c7882cbe1228f4040ef74 ("overflow: Reintroduce signed and unsigned overflow sanitizers")
https://git.kernel.org/cgit/linux/kernel/git/kees/linux.git devel/overflow/sanitizers

in testcase: boot

compiler: gcc-11
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(please refer to attached dmesg/kmsg for entire log/backtrace)


we noticed this commit is reintroducing "signed and unsigned overflow
sanitizers", there is below config diff between parent and this commit in our
buildings:

--- ea804316c9db5148d2bb0c1f40f70d7a83404638/.config    2024-01-26 22:09:35.046768122 +0800
+++ 660787b56e6e97ddc34c7882cbe1228f4040ef74/.config    2024-01-26 19:53:20.693434428 +0800
@@ -6706,6 +6706,7 @@ CONFIG_UBSAN_BOUNDS_STRICT=y
 CONFIG_UBSAN_SHIFT=y
 # CONFIG_UBSAN_DIV_ZERO is not set
 CONFIG_UBSAN_UNREACHABLE=y
+CONFIG_UBSAN_SIGNED_WRAP=y
 # CONFIG_UBSAN_BOOL is not set
 # CONFIG_UBSAN_ENUM is not set
 # CONFIG_UBSAN_ALIGNMENT is not set

while testing, we observed below different (and same part) between parent and
this commit:

ea804316c9db5148 660787b56e6e97ddc34c7882cbe
---------------- ---------------------------
       fail:runs  %reproduction    fail:runs
           |             |             |
          6:6            0%           6:6     dmesg.UBSAN:shift-out-of-bounds_in_arch/x86/kernel/cpu/intel.c
          6:6            0%           6:6     dmesg.UBSAN:shift-out-of-bounds_in_arch/x86/kernel/cpu/topology.c
          6:6            0%           6:6     dmesg.UBSAN:shift-out-of-bounds_in_fs/namespace.c
          6:6            0%           6:6     dmesg.UBSAN:shift-out-of-bounds_in_fs/read_write.c
          6:6            0%           6:6     dmesg.UBSAN:shift-out-of-bounds_in_include/linux/rhashtable.h
          6:6            0%           6:6     dmesg.UBSAN:shift-out-of-bounds_in_include/net/tcp.h
           :6          100%           6:6     dmesg.UBSAN:signed-integer-overflow_in_lib/test_memcat_p.c


this looks like the commit uncovered issue. but since it's hard for us to back
port this commit to each commit while bisecting, we cannot capture the real
first bad commit. not sure if this report could help somebody to investigate
the real issue?



If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-lkp/202401302219.db90a6d5-oliver.sang@xxxxxxxxx


[   42.894536][    T1] ------------[ cut here ]------------
[   42.895474][    T1] UBSAN: signed-integer-overflow in lib/test_memcat_p.c:47:10
[   42.897128][    T1] 6570 * 725861 cannot be represented in type 'int'
[   42.898391][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-rc1-00007-g660787b56e6e #1
[   42.899962][    T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[   42.901661][    T1] Call Trace:
[ 42.902009][ T1] dump_stack_lvl (??:?) 
[ 42.902009][ T1] dump_stack (??:?) 
[ 42.902009][ T1] handle_overflow (ubsan.c:?) 
[ 42.902009][ T1] ? kmemleak_alloc (??:?) 
[ 42.902009][ T1] ? kmalloc_trace (??:?) 
[ 42.902009][ T1] ? test_memcat_p_init (test_memcat_p.c:?) 
[ 42.902009][ T1] __ubsan_handle_mul_overflow (??:?) 
[ 42.902009][ T1] test_memcat_p_init (test_memcat_p.c:?) 
[ 42.902009][ T1] ? trace_hardirqs_on (??:?) 
[ 42.902009][ T1] ? _raw_spin_unlock_irqrestore (??:?) 
[ 42.902009][ T1] ? test_string_helpers_init (test_memcat_p.c:?) 
[ 42.902009][ T1] do_one_initcall (??:?) 
[ 42.902009][ T1] ? parameq (??:?) 
[ 42.902009][ T1] ? parse_args (??:?) 
[ 42.902009][ T1] do_initcalls (main.c:?) 
[ 42.902009][ T1] ? rdinit_setup (main.c:?) 
[ 42.902009][ T1] kernel_init_freeable (main.c:?) 
[ 42.902009][ T1] ? rest_init (main.c:?) 
[ 42.902009][ T1] kernel_init (main.c:?) 
[ 42.902009][ T1] ? schedule_tail (??:?) 
[ 42.902009][ T1] ret_from_fork (??:?) 
[ 42.902009][ T1] ? rest_init (main.c:?) 
[ 42.902009][ T1] ret_from_fork_asm (??:?) 
[ 42.902009][ T1] entry_INT80_32 (??:?) 
[   42.924183][    T1] ---[ end trace ]---
[   42.925743][    T1] test_memcat_p: test passed


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20240130/202401302219.db90a6d5-oliver.sang@xxxxxxxxx



-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki