Hello, syzbot found the following issue on: HEAD commit: ce8056d1 wip: changed copy_from_user where instrumented git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=10278e91900000 kernel config: https://syzkaller.appspot.com/x/.config?x=3afe005fb99591f dashboard link: https://syzkaller.appspot.com/bug?extid=6b02c1da3865f750164a compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=177d957a900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14528186900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6b02c1da3865f750164a@xxxxxxxxxxxxxxxxxxxxxxxxx sd 1:0:0:0: [sdb] 0 512-byte logical blocks: (0 B/0 B) sd 1:0:0:0: [sdb] 0-byte physical blocks ===================================================== BUG: KMSAN: uninit-value in scsi_mode_sense+0x10f0/0x17b0 drivers/scsi/scsi_lib.c:2138 CPU: 1 PID: 624 Comm: kworker/u4:6 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound async_run_entry_fn Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 scsi_mode_sense+0x10f0/0x17b0 drivers/scsi/scsi_lib.c:2138 sd_read_write_protect_flag drivers/scsi/sd.c:2636 [inline] sd_revalidate_disk+0x4ffa/0xdae0 drivers/scsi/sd.c:3175 sd_probe+0x10d1/0x18c0 drivers/scsi/sd.c:3405 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach_async_helper+0x31a/0x3f0 drivers/base/dd.c:833 async_run_entry_fn+0x1a2/0x7d0 kernel/async.c:123 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116 bio_copy_kern_endio_read+0x494/0x5f0 block/blk-map.c:448 bio_endio+0xce1/0xde0 block/bio.c:1447 req_bio_endio block/blk-core.c:261 [inline] blk_update_request+0x1178/0x2710 block/blk-core.c:1569 scsi_end_request+0x102/0xc00 drivers/scsi/scsi_lib.c:558 scsi_io_completion+0x34f/0x2f20 drivers/scsi/scsi_lib.c:934 scsi_finish_command+0x85b/0x880 drivers/scsi/scsi.c:214 scsi_softirq_done+0x683/0xa80 drivers/scsi/scsi_lib.c:1460 blk_done_softirq+0x2fe/0x4e0 block/blk-softirq.c:37 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:293 Uninit was created at: kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:269 [inline] kmsan_alloc_page+0xc5/0x1a0 mm/kmsan/kmsan_shadow.c:293 __alloc_pages_nodemask+0xdf0/0x1030 mm/page_alloc.c:4889 alloc_pages_current+0x685/0xb50 mm/mempolicy.c:2292 alloc_pages include/linux/gfp.h:545 [inline] bio_copy_kern block/blk-map.c:494 [inline] blk_rq_map_kern+0xdda/0x1570 block/blk-map.c:743 __scsi_execute+0x318/0xc80 drivers/scsi/scsi_lib.c:258 scsi_execute_req include/scsi/scsi_device.h:460 [inline] scsi_mode_sense+0x600/0x17b0 drivers/scsi/scsi_lib.c:2115 sd_read_write_protect_flag drivers/scsi/sd.c:2636 [inline] sd_revalidate_disk+0x4ffa/0xdae0 drivers/scsi/sd.c:3175 sd_probe+0x10d1/0x18c0 drivers/scsi/sd.c:3405 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach_async_helper+0x31a/0x3f0 drivers/base/dd.c:833 async_run_entry_fn+0x1a2/0x7d0 kernel/async.c:123 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 ===================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
