Messages in this thread | | | Subject | Re: general protection fault in j1939_netdev_notify (2) | From | Oliver Hartkopp <> | Date | Mon, 21 Dec 2020 13:25:47 +0100 |
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On 20.12.20 15:37, Oleksij Rempel wrote: > Hello Oliver, > > On Sun, Dec 20, 2020 at 02:18:27PM +0100, Oliver Hartkopp wrote: >> Hello Oleksij, >> >> I assume there is some ndev->ml_priv value set - but not from a CAN >> netdevice. > > it is kind of CAN device :)
No, it is not.
Team and bonding devices copy elements like dev->type but do not take care about the CAN specific ml_priv.
I don't know if this is the case here. I can take a look later.
>> What was the reason to fiddle with the 'priv' stuff in j1939_netdev_notify() >> before checking if it was a CAN device? >> >> Would this patch fix the issue then? > > No, j1939_priv_get_by_ndev() already has an internal test for > ARPHRD_CAN. One of this tests can be removed, to make the code clear. > So, we get netdev with ARPHRD_CAN and ml_priv == something. > > Right now I do not know how to fix it. > > Ideas?
IMO the patch is still an improvement as it swaps the testing and reduces complexity.
Regards, Oliver
> >> diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c >> index bb914d8b4216..6940f98b81fb 100644 >> --- a/net/can/j1939/main.c >> +++ b/net/can/j1939/main.c >> @@ -348,26 +348,25 @@ static int j1939_netdev_notify(struct notifier_block >> *nb, >> unsigned long msg, void *data) >> { >> struct net_device *ndev = netdev_notifier_info_to_dev(data); >> struct j1939_priv *priv; >> >> + if (ndev->type != ARPHRD_CAN) >> + goto notify_done; >> + >> priv = j1939_priv_get_by_ndev(ndev); >> if (!priv) >> goto notify_done; >> >> - if (ndev->type != ARPHRD_CAN) >> - goto notify_put; >> - >> switch (msg) { >> case NETDEV_DOWN: >> j1939_cancel_active_session(priv, NULL); >> j1939_sk_netdev_event_netdown(priv); >> j1939_ecu_unmap_all(priv); >> break; >> } >> >> -notify_put: >> j1939_priv_put(priv); >> >> notify_done: >> return NOTIFY_DONE; >> } >> >> If so, I can send a proper patch if you like. >> >> Best regards, >> Oliver >> >> >> On 20.12.20 06:34, syzbot wrote: >>> Hello, >>> >>> syzbot found the following issue on: >>> >>> HEAD commit: d635a69d Merge tag 'net-next-5.11' of git://git.kernel.org.. >>> git tree: upstream >>> console output: https://syzkaller.appspot.com/x/log.txt?x=1315f123500000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=c3556e4856b17a95 >>> dashboard link: https://syzkaller.appspot.com/bug?extid=5138c4dd15a0401bec7b >>> compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b) >>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12955123500000 >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10f2f30f500000 >>> >>> The issue was bisected to: >>> >>> commit 497a5757ce4e8f37219a3989ac6a561eb9a8e6c7 >>> Author: Heiner Kallweit <hkallweit1@gmail.com> >>> Date: Sat Nov 7 20:50:56 2020 +0000 >>> >>> tun: switch to net core provided statistics counters >>> >>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=143b845b500000 >>> final oops: https://syzkaller.appspot.com/x/report.txt?x=163b845b500000 >>> console output: https://syzkaller.appspot.com/x/log.txt?x=123b845b500000 >>> >>> IMPORTANT: if you fix the issue, please add the following tag to the commit: >>> Reported-by: syzbot+5138c4dd15a0401bec7b@syzkaller.appspotmail.com >>> Fixes: 497a5757ce4e ("tun: switch to net core provided statistics counters") >>> >>> general protection fault, probably for non-canonical address 0xe000080fe8c072f1: 0000 [#1] PREEMPT SMP KASAN >>> KASAN: probably user-memory-access in range [0x0000607f46039788-0x0000607f4603978f] >>> CPU: 1 PID: 8472 Comm: syz-executor635 Not tainted 5.10.0-syzkaller #0 >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >>> RIP: 0010:j1939_ndev_to_priv net/can/j1939/main.c:219 [inline] >>> RIP: 0010:j1939_priv_get_by_ndev_locked net/can/j1939/main.c:231 [inline] >>> RIP: 0010:j1939_priv_get_by_ndev net/can/j1939/main.c:243 [inline] >>> RIP: 0010:j1939_netdev_notify+0x115/0x320 net/can/j1939/main.c:353 >>> Code: 00 74 08 48 89 df e8 ba 1e 48 f9 48 8b 1b 48 85 db 0f 84 f0 00 00 00 4c 89 64 24 08 48 81 c3 28 60 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 8c 1e 48 f9 4c 8b 23 4d 85 e4 0f >>> RSP: 0018:ffffc90000e9fd68 EFLAGS: 00010202 >>> RAX: 00000c0fe8c072f1 RBX: 0000607f46039788 RCX: ffff88801456d040 >>> RDX: ffff88801456d040 RSI: 0000000000000118 RDI: 0000000000000118 >>> RBP: 0000000000000118 R08: ffffffff8870585d R09: fffff520001d3fa5 >>> R10: fffff520001d3fa5 R11: 0000000000000000 R12: 0000000000000010 >>> R13: 1ffff1100293e848 R14: dffffc0000000000 R15: ffff8880149f4244 >>> FS: 0000000001d13880(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: 0000000020000080 CR3: 000000001402f000 CR4: 00000000001506e0 >>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >>> Call Trace: >>> notifier_call_chain kernel/notifier.c:83 [inline] >>> raw_notifier_call_chain+0xe7/0x170 kernel/notifier.c:410 >>> call_netdevice_notifiers_info net/core/dev.c:2022 [inline] >>> call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] >>> call_netdevice_notifiers+0xeb/0x150 net/core/dev.c:2048 >>> __tun_chr_ioctl+0x2337/0x4860 drivers/net/tun.c:3093 >>> vfs_ioctl fs/ioctl.c:48 [inline] >>> __do_sys_ioctl fs/ioctl.c:753 [inline] >>> __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 >>> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >>> entry_SYSCALL_64_after_hwframe+0x44/0xa9 >>> RIP: 0033:0x440359 >>> Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 >>> RSP: 002b:00007fffd37b9c98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 >>> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440359 >>> RDX: 0000000000000118 RSI: 00000000400454cd RDI: 0000000000000003 >>> RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 >>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b60 >>> R13: 0000000000401bf0 R14: 0000000000000000 R15: 0000000000000000 >>> Modules linked in: >>> ---[ end trace 7688a2c3c10da2e1 ]--- >>> RIP: 0010:j1939_ndev_to_priv net/can/j1939/main.c:219 [inline] >>> RIP: 0010:j1939_priv_get_by_ndev_locked net/can/j1939/main.c:231 [inline] >>> RIP: 0010:j1939_priv_get_by_ndev net/can/j1939/main.c:243 [inline] >>> RIP: 0010:j1939_netdev_notify+0x115/0x320 net/can/j1939/main.c:353 >>> Code: 00 74 08 48 89 df e8 ba 1e 48 f9 48 8b 1b 48 85 db 0f 84 f0 00 00 00 4c 89 64 24 08 48 81 c3 28 60 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 8c 1e 48 f9 4c 8b 23 4d 85 e4 0f >>> RSP: 0018:ffffc90000e9fd68 EFLAGS: 00010202 >>> RAX: 00000c0fe8c072f1 RBX: 0000607f46039788 RCX: ffff88801456d040 >>> RDX: ffff88801456d040 RSI: 0000000000000118 RDI: 0000000000000118 >>> RBP: 0000000000000118 R08: ffffffff8870585d R09: fffff520001d3fa5 >>> R10: fffff520001d3fa5 R11: 0000000000000000 R12: 0000000000000010 >>> R13: 1ffff1100293e848 R14: dffffc0000000000 R15: ffff8880149f4244 >>> FS: 0000000001d13880(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: 0000000020000080 CR3: 000000001402f000 CR4: 00000000001506e0 >>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >>> >>> >>> --- >>> 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@googlegroups.com. >>> >>> syzbot will keep track of this issue. 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 issue, for details see: >>> https://goo.gl/tpsmEJ#testing-patches >>> >> >
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