bisecting fixing commit since 9a95f25269bd9257ab9fba7bb14355d50b5f39ec building syzkaller on c8e81ce4c7e3b59e7c83c6fab56c217916f3b3b6 testing commit 9a95f25269bd9257ab9fba7bb14355d50b5f39ec compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: abe8e05ef5d091a5655f4a0d21c144fb2d4475f0f8b15e3fd82ea11ebabbcf64 run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in blk_mq_map_swqueue run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in blk_mq_map_swqueue run #2: crashed: BUG: unable to handle kernel run #3: crashed: BUG: unable to handle kernel run #4: crashed: BUG: unable to handle kernel run #5: crashed: BUG: unable to handle kernel run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in blk_mq_map_swqueue run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in blk_mq_map_swqueue run #8: crashed: BUG: unable to handle kernel run #9: crashed: BUG: unable to handle kernel run #10: crashed: BUG: unable to handle kernel run #11: crashed: BUG: unable to handle kernel NULL pointer dereference in blk_mq_map_swqueue run #12: crashed: BUG: unable to handle kernel run #13: crashed: BUG: unable to handle kernel NULL pointer dereference in blk_mq_map_swqueue run #14: crashed: BUG: unable to handle kernel run #15: crashed: BUG: unable to handle kernel run #16: crashed: BUG: unable to handle kernel NULL pointer dereference in blk_mq_map_swqueue run #17: crashed: BUG: unable to handle kernel run #18: crashed: BUG: unable to handle kernel run #19: crashed: BUG: unable to handle kernel testing current HEAD 4ba8e26127c393c32776dff6d79c5b82de6dc542 testing commit 4ba8e26127c393c32776dff6d79c5b82de6dc542 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 04c9c63f72ee2b565376e564635226f6e6f5a704e413142bb121708b1db24f19 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 28m1.864501083s (build: 20m17.997022377s, test: 6m17.31900235s) the crash still happens on HEAD commit msg: Linux 4.14.262 crash: unregister_netdevice: waiting for DEV to become free can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1