If bisect was right with this: > >The bug was bisected to: > > > >commit 9868b5d44f3df9dd75247acd23dddff0a42f79be > >Author: Kurt Van Dijck <dev.kurt@xxxxxxxxxxxxxxxxxxxxxx> > >Date: Mon Oct 8 09:48:33 2018 +0000 > > > > can: introduce CAN_REQUIRED_SIZE macro Then I'd start looking in malformed sockaddr_can data instead. Is this code what triggers the bug? > >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=138f5db9e00000 Kind regards, Kurt On vr, 17 jan 2020 21:02:48 +0100, Oliver Hartkopp wrote: > Hi Marc, Oleksij, Kurt, > > On 17/01/2020 14.46, syzbot wrote: > >Hello, > > > >syzbot found the following crash on: > > > >HEAD commit: f5ae2ea6 Fix built-in early-load Intel microcode alignment > >git tree: upstream > >console output: https://syzkaller.appspot.com/x/log.txt?x=1033df15e00000 > >kernel config: https://syzkaller.appspot.com/x/.config?x=cfbb8fa33f49f9f3 > >dashboard link: > >https://syzkaller.appspot.com/bug?extid=c3ea30e1e2485573f953 > >compiler: clang version 10.0.0 > >(https://github.com/llvm/llvm-project/ > >c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > >syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13204f15e00000 > >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=138f5db9e00000 > > > >The bug was bisected to: > > > >commit 9868b5d44f3df9dd75247acd23dddff0a42f79be > >Author: Kurt Van Dijck <dev.kurt@xxxxxxxxxxxxxxxxxxxxxx> > >Date: Mon Oct 8 09:48:33 2018 +0000 > > > > can: introduce CAN_REQUIRED_SIZE macro > > > >bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=129bfdb9e00000 > >final crash: https://syzkaller.appspot.com/x/report.txt?x=119bfdb9e00000 > >console output: https://syzkaller.appspot.com/x/log.txt?x=169bfdb9e00000 > > > >IMPORTANT: if you fix the bug, please add the following tag to the commit: > >Reported-by: syzbot+c3ea30e1e2485573f953@xxxxxxxxxxxxxxxxxxxxxxxxx > >Fixes: 9868b5d44f3d ("can: introduce CAN_REQUIRED_SIZE macro") > > > >kasan: CONFIG_KASAN_INLINE enabled > >kasan: GPF could be caused by NULL-ptr deref or user memory access > >general protection fault: 0000 [#1] PREEMPT SMP KASAN > >CPU: 0 PID: 9593 Comm: syz-executor302 Not tainted 5.5.0-rc6-syzkaller #0 > >Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > >Google 01/01/2011 > >RIP: 0010:hlist_add_head_rcu include/linux/rculist.h:528 [inline] > >RIP: 0010:can_rx_register+0x43b/0x600 net/can/af_can.c:476 > > include/linux/rculist.h:528 is > > struct hlist_node *first = h->first; > > which would mean that 'h' must be NULL. > > But the h parameter is rcv_list from > rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists); > > Which can not return NULL - at least when dev_rcv_lists is a proper pointer > to the dev_rcv_lists provided by can_dev_rcv_lists_find(). > > So either dev->ml_priv is NULL in the case of having a CAN interface (here > vxcan) or we have not allocated net->can.rx_alldev_list in can_pernet_init() > properly (which would lead to an -ENOMEM which is reported to whom?). > > Hm. I'm lost. Any ideas? > > Regards, > Oliver > > > >Code: 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 89 22 8a fa 4c > >89 33 4d 89 e5 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <41> 80 7c 05 00 > >00 74 08 4c 89 e7 e8 c5 21 8a fa 4d 8b 34 24 4c 89 > >RSP: 0018:ffffc90003e27d00 EFLAGS: 00010202 > >RAX: dffffc0000000000 RBX: ffff8880a77336c8 RCX: ffff88809306a100 > >RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a77336c0 > >RBP: ffffc90003e27d58 R08: ffffffff87289cd6 R09: fffff520007c4f94 > >R10: fffff520007c4f94 R11: 0000000000000000 R12: 0000000000000008 > >R13: 0000000000000001 R14: ffff88809fbcf000 R15: ffff8880a7733690 > >FS: 00007fb132f26700(0000) GS:ffff8880aec00000(0000) > >knlGS:0000000000000000 > >CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >CR2: 000000000178f590 CR3: 00000000996d6000 CR4: 00000000001406f0 > >DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > >Call Trace: > > raw_enable_filters net/can/raw.c:189 [inline] > > raw_enable_allfilters net/can/raw.c:255 [inline] > > raw_bind+0x326/0x1230 net/can/raw.c:428 > > __sys_bind+0x2bd/0x3a0 net/socket.c:1649 > > __do_sys_bind net/socket.c:1660 [inline] > > __se_sys_bind net/socket.c:1658 [inline] > > __x64_sys_bind+0x7a/0x90 net/socket.c:1658 > > do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > >RIP: 0033:0x446ba9 > >Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 > >48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > >ff 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > >RSP: 002b:00007fb132f25d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 > >RAX: ffffffffffffffda RBX: 00000000006dbc88 RCX: 0000000000446ba9 > >RDX: 0000000000000008 RSI: 0000000020000180 RDI: 0000000000000003 > >RBP: 00000000006dbc80 R08: 00007fb132f26700 R09: 0000000000000000 > >R10: 00007fb132f26700 R11: 0000000000000246 R12: 00000000006dbc8c > >R13: 0000000000000000 R14: 0000000000000000 R15: 068500100000003c > >Modules linked in: > >---[ end trace 0dedabb13ca8e7d7 ]--- > >RIP: 0010:hlist_add_head_rcu include/linux/rculist.h:528 [inline] > >RIP: 0010:can_rx_register+0x43b/0x600 net/can/af_can.c:476 > >Code: 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 89 22 8a fa 4c > >89 33 4d 89 e5 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <41> 80 7c 05 00 > >00 74 08 4c 89 e7 e8 c5 21 8a fa 4d 8b 34 24 4c 89 > >RSP: 0018:ffffc90003e27d00 EFLAGS: 00010202 > >RAX: dffffc0000000000 RBX: ffff8880a77336c8 RCX: ffff88809306a100 > >RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a77336c0 > >RBP: ffffc90003e27d58 R08: ffffffff87289cd6 R09: fffff520007c4f94 > >R10: fffff520007c4f94 R11: 0000000000000000 R12: 0000000000000008 > >R13: 0000000000000001 R14: ffff88809fbcf000 R15: ffff8880a7733690 > >FS: 00007fb132f26700(0000) GS:ffff8880aec00000(0000) > >knlGS:0000000000000000 > >CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >CR2: 000000000178f590 CR3: 00000000996d6000 CR4: 00000000001406f0 > >DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > > > >--- > >This bug 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 bug report. See: > >https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > >For information about bisection process see: > >https://goo.gl/tpsmEJ#bisection > >syzbot can test patches for this bug, for details see: > >https://goo.gl/tpsmEJ#testing-patches
