On Wed, Jan 5, 2022 at 3:20 AM syzbot <syzbot+4c63f36709a642f801c5@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > syzbot has found a reproducer for the following issue on: > > HEAD commit: c9e6606c7fe9 Linux 5.16-rc8 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=148351c3b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=32f9fa260d7413b4 > dashboard link: https://syzkaller.appspot.com/bug?extid=4c63f36709a642f801c5 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15435e2bb00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12f4508db00000 > This C repro looks legit, bug should be in CAN layer. > The issue was bisected to: > > commit e4b8954074f6d0db01c8c97d338a67f9389c042f > Author: Eric Dumazet <edumazet@xxxxxxxxxx> > Date: Tue Dec 7 01:30:37 2021 +0000 > > netlink: add net device refcount tracker to struct ethnl_req_info Ignore this bisection, an unrelated commit whent in its way. > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=109e6fcbb00000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=129e6fcbb00000 > console output: https://syzkaller.appspot.com/x/log.txt?x=149e6fcbb00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+4c63f36709a642f801c5@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: e4b8954074f6 ("netlink: add net device refcount tracker to struct ethnl_req_info") > > skbuff: skb_over_panic: text:ffffffff88235fb8 len:4096 put:4096 head:ffff888021cb8400 data:ffff888021cb8400 tail:0x1000 end:0xc0 dev:<NULL> > ------------[ cut here ]------------ > kernel BUG at net/core/skbuff.c:113! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.16.0-rc8-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:113 > Code: f8 4c 8b 4c 24 10 8b 4b 70 41 56 45 89 e8 4c 89 e2 41 57 48 89 ee 48 c7 c7 e0 4b ad 8a ff 74 24 10 ff 74 24 20 e8 6e 24 c2 ff <0f> 0b e8 74 92 38 f8 4c 8b 64 24 18 e8 da 47 7f f8 48 c7 c1 80 58 > RSP: 0018:ffffc90000d979e0 EFLAGS: 00010286 > RAX: 000000000000008b RBX: ffff888021ccb500 RCX: 0000000000000000 > RDX: ffff88801196d700 RSI: ffffffff815f0948 RDI: fffff520001b2f2e > RBP: ffffffff8aad58c0 R08: 000000000000008b R09: 0000000000000000 > R10: ffffffff815ea6ee R11: 0000000000000000 R12: ffffffff88235fb8 > R13: 0000000000001000 R14: ffffffff8aad4ba0 R15: 00000000000000c0 > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f886c8cc718 CR3: 000000007ad6d000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > skb_over_panic net/core/skbuff.c:118 [inline] > skb_put.cold+0x24/0x24 net/core/skbuff.c:1990 > isotp_rcv_cf net/can/isotp.c:570 [inline] > isotp_rcv+0xa38/0x1e30 net/can/isotp.c:668 > deliver net/can/af_can.c:574 [inline] > can_rcv_filter+0x445/0x8d0 net/can/af_can.c:635 > can_receive+0x31d/0x580 net/can/af_can.c:665 > can_rcv+0x120/0x1c0 net/can/af_can.c:696 > __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5465 > __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5579 > process_backlog+0x2a5/0x6c0 net/core/dev.c:6455 > __napi_poll+0xaf/0x440 net/core/dev.c:7023 > napi_poll net/core/dev.c:7090 [inline] > net_rx_action+0x801/0xb40 net/core/dev.c:7177 > __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 > run_ksoftirqd kernel/softirq.c:921 [inline] > run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913 > smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 > kthread+0x405/0x4f0 kernel/kthread.c:327 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > </TASK> > Modules linked in: > ---[ end trace 9f06028ec4daf4be ]--- > RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:113 > Code: f8 4c 8b 4c 24 10 8b 4b 70 41 56 45 89 e8 4c 89 e2 41 57 48 89 ee 48 c7 c7 e0 4b ad 8a ff 74 24 10 ff 74 24 20 e8 6e 24 c2 ff <0f> 0b e8 74 92 38 f8 4c 8b 64 24 18 e8 da 47 7f f8 48 c7 c1 80 58 > RSP: 0018:ffffc90000d979e0 EFLAGS: 00010286 > RAX: 000000000000008b RBX: ffff888021ccb500 RCX: 0000000000000000 > RDX: ffff88801196d700 RSI: ffffffff815f0948 RDI: fffff520001b2f2e > RBP: ffffffff8aad58c0 R08: 000000000000008b R09: 0000000000000000 > R10: ffffffff815ea6ee R11: 0000000000000000 R12: ffffffff88235fb8 > R13: 0000000000001000 R14: ffffffff8aad4ba0 R15: 00000000000000c0 > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f886c8cc718 CR3: 000000007ad6d000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >
