Hello, syzbot found the following issue on: HEAD commit: a74e6a01 Merge tag 's390-5.12-3' of git://git.kernel.org/p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=159f69ecd00000 kernel config: https://syzkaller.appspot.com/x/.config?x=de394bbaade74fb7 dashboard link: https://syzkaller.appspot.com/bug?extid=30774a6acf6a2cf6d535 compiler: Debian clang version 11.0.1-2 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+30774a6acf6a2cf6d535@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KCSAN: data-race in start_this_handle / start_this_handle write to 0xffff888103880870 of 8 bytes by task 29956 on cpu 1: jbd2_get_transaction fs/jbd2/transaction.c:125 [inline] start_this_handle+0xceb/0x1010 fs/jbd2/transaction.c:400 jbd2__journal_start+0x1fc/0x3f0 fs/jbd2/transaction.c:503 __ext4_journal_start_sb+0x159/0x310 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:320 [inline] ext4_da_write_begin+0x460/0xaf0 fs/ext4/inode.c:2998 generic_perform_write+0x196/0x3a0 mm/filemap.c:3575 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:269 ext4_file_write_iter+0x48a/0x10b0 fs/ext4/file.c:502 call_write_iter include/linux/fs.h:1977 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x7a6/0xe20 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1311 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888103880870 of 8 bytes by task 29936 on cpu 0: start_this_handle+0x1c1/0x1010 fs/jbd2/transaction.c:352 jbd2__journal_start+0x1fc/0x3f0 fs/jbd2/transaction.c:503 __ext4_journal_start_sb+0x159/0x310 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:320 [inline] ext4_da_write_begin+0x460/0xaf0 fs/ext4/inode.c:2998 generic_perform_write+0x196/0x3a0 mm/filemap.c:3575 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:269 ext4_file_write_iter+0x48a/0x10b0 fs/ext4/file.c:502 call_write_iter include/linux/fs.h:1977 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x7a6/0xe20 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1311 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 29936 Comm: syz-executor.5 Not tainted 5.12.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== --- 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.
