Hello, syzbot found the following issue on: HEAD commit: fbafc3e621c3 Merge tag 'for_linus' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16e43009e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=e0c7078a6b901aa3 dashboard link: https://syzkaller.appspot.com/bug?extid=47a017c46edb25eff048 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/1520f7b6daa4/disk-fbafc3e6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8b490af009d5/vmlinux-fbafc3e6.xz kernel image: https://storage.googleapis.com/syzbot-assets/202ca200f4a4/bzImage-fbafc3e6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+47a017c46edb25eff048@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+0x43c/0xd80 lib/crc32.c:197 crc32_body lib/crc32.c:110 [inline] crc32_le_generic lib/crc32.c:179 [inline] crc32_le_base+0x43c/0xd80 lib/crc32.c:197 nilfs_segbuf_fill_in_data_crc fs/nilfs2/segbuf.c:224 [inline] nilfs_add_checksums_on_logs+0xbe4/0xf60 fs/nilfs2/segbuf.c:327 nilfs_segctor_do_construct+0x9eff/0xe050 fs/nilfs2/segment.c:2112 nilfs_segctor_construct+0x1eb/0xe30 fs/nilfs2/segment.c:2415 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2523 [inline] nilfs_segctor_thread+0xc3f/0x11d0 fs/nilfs2/segment.c:2606 kthread+0x3ed/0x540 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Uninit was created at: __alloc_pages+0x9a4/0xe00 mm/page_alloc.c:4591 alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133 alloc_pages mm/mempolicy.c:2204 [inline] folio_alloc+0x1da/0x380 mm/mempolicy.c:2211 filemap_alloc_folio+0xa5/0x430 mm/filemap.c:974 __filemap_get_folio+0xa5a/0x1760 mm/filemap.c:1918 pagecache_get_page+0x4a/0x1a0 mm/folio-compat.c:99 grab_cache_page_write_begin+0x55/0x70 mm/folio-compat.c:109 block_write_begin+0x4f/0x450 fs/buffer.c:2223 nilfs_write_begin+0xfc/0x200 fs/nilfs2/inode.c:261 generic_perform_write+0x3f5/0xc40 mm/filemap.c:3918 __generic_file_write_iter+0x20a/0x460 mm/filemap.c:4013 generic_file_write_iter+0x103/0x5b0 mm/filemap.c:4039 __kernel_write_iter+0x329/0x930 fs/read_write.c:517 dump_emit_page fs/coredump.c:888 [inline] dump_user_range+0x593/0xcd0 fs/coredump.c:915 elf_core_dump+0x528d/0x5a40 fs/binfmt_elf.c:2077 do_coredump+0x32c9/0x4920 fs/coredump.c:764 get_signal+0x2185/0x2d10 kernel/signal.c:2890 arch_do_signal_or_restart+0x53/0xca0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop+0xe8/0x320 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x163/0x220 kernel/entry/common.c:204 irqentry_exit_to_user_mode+0xd/0x30 kernel/entry/common.c:309 irqentry_exit+0x16/0x40 kernel/entry/common.c:412 exc_page_fault+0x246/0x6f0 arch/x86/mm/fault.c:1564 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:570 CPU: 1 PID: 5307 Comm: segctord Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 ===================================================== --- 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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
