Hi Oliver, On Thu, Nov 03, 2022 at 10:21:15PM +0100, Oliver Hartkopp wrote: > Good catch! > > That's a correct issue caused by only filling the CAN frame header with > can_id and len in j1939_send_one(): > > https://elixir.bootlin.com/linux/v6.0.6/source/net/can/j1939/main.c#L345 > > @Oleksij: Can you please (zero)initialize the unused elements in struct > can_frame (namely __pad, __res0, len8_dlc) in j1939_send_one()? > > Or do you want me to create a patch for it? I'll not be able to make it today. I'll be glad if you could do it Thanks and best regards, Oleksij > > On 03.11.22 17:22, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 4a3e741a3d6a x86: fortify: kmsan: fix KMSAN fortify builds > > git tree: https://github.com/google/kmsan.git master > > console+strace: https://syzkaller.appspot.com/x/log.txt?x=14247636880000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=c19210a0c25eebb > > dashboard link: https://syzkaller.appspot.com/bug?extid=d168ec0caca4697e03b1 > > compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project.git 610139d2d9ce6746b3c617fb3e2f7886272d26ff), GNU ld (GNU Binutils for Debian) 2.35.2 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13e16e86880000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1535a2f6880000 > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/fbb1997bc1e0/disk-4a3e741a.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/d5dd2e1efaa4/vmlinux-4a3e741a.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+d168ec0caca4697e03b1@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ===================================================== > > BUG: KMSAN: uninit-value in can_is_canxl_skb include/linux/can/skb.h:128 [inline] > > BUG: KMSAN: uninit-value in can_send+0x269/0x1100 net/can/af_can.c:205 > > can_is_canxl_skb include/linux/can/skb.h:128 [inline] > > can_send+0x269/0x1100 net/can/af_can.c:205 > > j1939_send_one+0x40f/0x4d0 net/can/j1939/main.c:352 > > j1939_xtp_do_tx_ctl+0x69f/0x9e0 net/can/j1939/transport.c:664 > > j1939_tp_tx_ctl net/can/j1939/transport.c:672 [inline] > > j1939_session_tx_rts net/can/j1939/transport.c:740 [inline] > > j1939_xtp_txnext_transmiter net/can/j1939/transport.c:880 [inline] > > j1939_tp_txtimer+0x35bb/0x4520 net/can/j1939/transport.c:1158 > > __run_hrtimer+0x298/0x910 kernel/time/hrtimer.c:1685 > > __hrtimer_run_queues kernel/time/hrtimer.c:1749 [inline] > > hrtimer_run_softirq+0x4b0/0x870 kernel/time/hrtimer.c:1766 > > __do_softirq+0x1c5/0x7b9 kernel/softirq.c:571 > > invoke_softirq+0x8f/0x100 kernel/softirq.c:445 > > __irq_exit_rcu+0x5a/0x110 kernel/softirq.c:650 > > irq_exit_rcu+0xe/0x10 kernel/softirq.c:662 > > sysvec_apic_timer_interrupt+0x9a/0xc0 arch/x86/kernel/apic/apic.c:1107 > > asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 > > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] > > _raw_spin_unlock_irqrestore+0x2f/0x50 kernel/locking/spinlock.c:194 > > unlock_hrtimer_base kernel/time/hrtimer.c:1017 [inline] > > hrtimer_start_range_ns+0xaba/0xb50 kernel/time/hrtimer.c:1301 > > hrtimer_start include/linux/hrtimer.h:418 [inline] > > j1939_tp_schedule_txtimer+0xbe/0x100 net/can/j1939/transport.c:697 > > j1939_sk_send_loop net/can/j1939/socket.c:1143 [inline] > > j1939_sk_sendmsg+0x1c2c/0x25d0 net/can/j1939/socket.c:1256 > > sock_sendmsg_nosec net/socket.c:714 [inline] > > sock_sendmsg net/socket.c:734 [inline] > > ____sys_sendmsg+0xa8e/0xe70 net/socket.c:2482 > > ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2536 > > __sys_sendmsg net/socket.c:2565 [inline] > > __do_sys_sendmsg net/socket.c:2574 [inline] > > __se_sys_sendmsg net/socket.c:2572 [inline] > > __x64_sys_sendmsg+0x367/0x540 net/socket.c:2572 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > Uninit was created at: > > slab_post_alloc_hook mm/slab.h:742 [inline] > > slab_alloc_node mm/slub.c:3398 [inline] > > __kmem_cache_alloc_node+0x6ee/0xc90 mm/slub.c:3437 > > __do_kmalloc_node mm/slab_common.c:954 [inline] > > __kmalloc_node_track_caller+0x117/0x3d0 mm/slab_common.c:975 > > kmalloc_reserve net/core/skbuff.c:437 [inline] > > __alloc_skb+0x34a/0xca0 net/core/skbuff.c:509 > > alloc_skb include/linux/skbuff.h:1267 [inline] > > j1939_tp_tx_dat_new net/can/j1939/transport.c:593 [inline] > > j1939_xtp_do_tx_ctl+0xa3/0x9e0 net/can/j1939/transport.c:654 > > j1939_tp_tx_ctl net/can/j1939/transport.c:672 [inline] > > j1939_session_tx_rts net/can/j1939/transport.c:740 [inline] > > j1939_xtp_txnext_transmiter net/can/j1939/transport.c:880 [inline] > > j1939_tp_txtimer+0x35bb/0x4520 net/can/j1939/transport.c:1158 > > __run_hrtimer+0x298/0x910 kernel/time/hrtimer.c:1685 > > __hrtimer_run_queues kernel/time/hrtimer.c:1749 [inline] > > hrtimer_run_softirq+0x4b0/0x870 kernel/time/hrtimer.c:1766 > > __do_softirq+0x1c5/0x7b9 kernel/softirq.c:571 > > > > CPU: 0 PID: 3506 Comm: syz-executor289 Not tainted 6.1.0-rc2-syzkaller-61955-g4a3e741a3d6a #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 > > ===================================================== > > > > > > --- > > 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 > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
