Hi John, First bad commit (maybe != root cause): tree: https://android.googlesource.com/kernel/common android12-5.4 head: 82c67a98c7494b4e71dcbea03335509e9ccecfa5 commit: e3919bfeb0066ab9b5f9765e5610b95672990e64 [5/9] ANDROID: dma-buf: system_heap: Add deferred freeing to the system heap config: x86_64-rhel-8.3-kselftests (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.4-dirty git remote add android-common https://android.googlesource.com/kernel/common git fetch --no-tags android-common android12-5.4 git checkout e3919bfeb0066ab9b5f9765e5610b95672990e64 # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/dma-buf/heaps/ tools/virtio/vhost_test/vhost_test.ko If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) vim +/freelist_waitqueue +23 drivers/dma-buf/heaps/deferred-free-helper.c bd1639945c30298 John Stultz 2020-12-09 20 bd1639945c30298 John Stultz 2020-12-09 21 static LIST_HEAD(free_list); bd1639945c30298 John Stultz 2020-12-09 22 static size_t list_nr_pages; bd1639945c30298 John Stultz 2020-12-09 @23 wait_queue_head_t freelist_waitqueue; bd1639945c30298 John Stultz 2020-12-09 @24 struct task_struct *freelist_task; bd1639945c30298 John Stultz 2020-12-09 25 static DEFINE_SPINLOCK(free_list_lock); bd1639945c30298 John Stultz 2020-12-09 26 :::::: The code at line 23 was first introduced by commit :::::: bd1639945c30298e4bea2b611d6b0cd08d3cdd98 ANDROID: dma-buf: heaps: Add deferred-free-helper library code :::::: TO: John Stultz <john.stultz(a)linaro.org&gt; :::::: CC: John Stultz <john.stultz(a)linaro.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org