Hello, syzbot found the following issue on: HEAD commit: 73d62e81 kmsan: random: prevent boot-time reports in _mix_.. git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=120020acd00000 kernel config: https://syzkaller.appspot.com/x/.config?x=31d3b433c9628854 dashboard link: https://syzkaller.appspot.com/bug?extid=ce18ece82e1fede33bf7 compiler: clang version 11.0.1 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ce18ece82e1fede33bf7@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in crc32_body lib/crc32.c:110 [inline] BUG: KMSAN: uninit-value in crc32_le_generic lib/crc32.c:179 [inline] BUG: KMSAN: uninit-value in crc32_le_base+0x558/0xe70 lib/crc32.c:197 CPU: 1 PID: 11631 Comm: segctord Not tainted 5.10.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197 crc32_body lib/crc32.c:110 [inline] crc32_le_generic lib/crc32.c:179 [inline] crc32_le_base+0x558/0xe70 lib/crc32.c:197 nilfs_segbuf_fill_in_segsum_crc fs/nilfs2/segbuf.c:182 [inline] nilfs_add_checksums_on_logs+0x388/0xde0 fs/nilfs2/segbuf.c:320 nilfs_segctor_do_construct+0x7dd6/0xbf20 fs/nilfs2/segment.c:2072 nilfs_segctor_construct+0x302/0x1040 fs/nilfs2/segment.c:2377 nilfs_segctor_thread_construct+0xd6/0x840 fs/nilfs2/segment.c:2485 nilfs_segctor_thread+0xf35/0x13c0 fs/nilfs2/segment.c:2568 kthread+0x51c/0x560 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110 nilfs_write_dat_node_binfo+0x17a/0x370 fs/nilfs2/segment.c:663 nilfs_segctor_update_payload_blocknr fs/nilfs2/segment.c:1602 [inline] nilfs_segctor_assign fs/nilfs2/segment.c:1625 [inline] nilfs_segctor_do_construct+0x4b00/0xbf20 fs/nilfs2/segment.c:2052 nilfs_segctor_construct+0x302/0x1040 fs/nilfs2/segment.c:2377 nilfs_segctor_thread_construct+0xd6/0x840 fs/nilfs2/segment.c:2485 nilfs_segctor_thread+0xf35/0x13c0 fs/nilfs2/segment.c:2568 kthread+0x51c/0x560 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Local variable ----binfo.i.i@nilfs_segctor_do_construct created at: nilfs_segctor_update_payload_blocknr fs/nilfs2/segment.c:1558 [inline] nilfs_segctor_assign fs/nilfs2/segment.c:1625 [inline] nilfs_segctor_do_construct+0x3deb/0xbf20 fs/nilfs2/segment.c:2052 nilfs_segctor_update_payload_blocknr fs/nilfs2/segment.c:1558 [inline] nilfs_segctor_assign fs/nilfs2/segment.c:1625 [inline] nilfs_segctor_do_construct+0x3deb/0xbf20 fs/nilfs2/segment.c:2052 ===================================================== --- 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.
