On Mon, 24 Apr 2023 at 10:17, syzbot <syzbot+ebc945fdb4acd72cba78@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 148341f0a2f5 Merge tag 'vfs.misc.fixes.v6.3-rc6' of git://.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=14a62269c80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=54d63ee086ae78d0 > dashboard link: https://syzkaller.appspot.com/bug?extid=ebc945fdb4acd72cba78 > compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/1c557f92a6e1/disk-148341f0.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/f2c85210e1ce/vmlinux-148341f0.xz > kernel image: https://storage.googleapis.com/syzbot-assets/b019d0447709/bzImage-148341f0.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ebc945fdb4acd72cba78@xxxxxxxxxxxxxxxxxxxxxxxxx If I am reading this correctly, rxrpc_send_data() can read wrong call->completion and state and incorrectly exit with an error if rxrpc_wait_to_be_connected() exists early right after observing error set here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/rxrpc/sendmsg.c?id=148341f0a2f53b5e8808d093333d85170586a15d#n58 The code seems to assume that at that point all writes done by rxrpc_set_call_completion() are already finished, but it's not necessarily the case. > ================================================================== > BUG: KCSAN: data-race in rxrpc_send_data / rxrpc_set_call_completion > > write to 0xffff888159cf3c50 of 4 bytes by task 25673 on cpu 1: > rxrpc_set_call_completion+0x71/0x1c0 net/rxrpc/call_state.c:22 > rxrpc_send_data_packet+0xba9/0x1650 net/rxrpc/output.c:479 > rxrpc_transmit_one+0x1e/0x130 net/rxrpc/output.c:714 > rxrpc_decant_prepared_tx net/rxrpc/call_event.c:326 [inline] > rxrpc_transmit_some_data+0x496/0x600 net/rxrpc/call_event.c:350 > rxrpc_input_call_event+0x564/0x1220 net/rxrpc/call_event.c:464 > rxrpc_io_thread+0x307/0x1d80 net/rxrpc/io_thread.c:461 > kthread+0x1ac/0x1e0 kernel/kthread.c:376 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 > > read to 0xffff888159cf3c50 of 4 bytes by task 25672 on cpu 0: > rxrpc_send_data+0x29e/0x1950 net/rxrpc/sendmsg.c:296 > rxrpc_do_sendmsg+0xb7a/0xc20 net/rxrpc/sendmsg.c:726 > rxrpc_sendmsg+0x413/0x520 net/rxrpc/af_rxrpc.c:565 > sock_sendmsg_nosec net/socket.c:724 [inline] > sock_sendmsg net/socket.c:747 [inline] > ____sys_sendmsg+0x375/0x4c0 net/socket.c:2501 > ___sys_sendmsg net/socket.c:2555 [inline] > __sys_sendmmsg+0x263/0x500 net/socket.c:2641 > __do_sys_sendmmsg net/socket.c:2670 [inline] > __se_sys_sendmmsg net/socket.c:2667 [inline] > __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2667 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > value changed: 0x00000000 -> 0xffffffea > > Reported by Kernel Concurrency Sanitizer on: > CPU: 0 PID: 25672 Comm: syz-executor.5 Not tainted 6.3.0-rc5-syzkaller-00005-g148341f0a2f5 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 > ================================================================== > > > --- > 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. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000e7c6d205fa10a3cd%40google.com.
