[syzbot] [net?] general protection fault in hfsc_tcf_block

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c2b2ee36250d bridge: cfm: fix enum typo in br_cc_ccm_tx_pa..
git tree: net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=125321a1e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=a4e9ca8e3c104d2a
dashboard link: https://syzkaller.appspot.com/bug?extid=0039110f932d438130f9
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=123c0065e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17a8c0f6e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7344dc892eab/disk-c2b2ee36.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b5d04995c162/vmlinux-c2b2ee36.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9558856ab7f4/bzImage-c2b2ee36.xz

The issue was bisected to:

commit 913b47d3424e7d99eaf34b798c47dfa840c64a08
Author: Victor Nogueira <vic...@mojatatu.com>
Date: Tue Dec 19 18:16:19 2023 +0000

net/sched: Introduce tc block netdev tracking infra

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1235de8de80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1135de8de80000
console output: https://syzkaller.appspot.com/x/log.txt?x=1635de8de80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+003911...@syzkaller.appspotmail.com
Fixes: 913b47d3424e ("net/sched: Introduce tc block netdev tracking infra")

general protection fault, probably for non-canonical address 0xdffffc0000002009: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x0000000000010048-0x000000000001004f]
CPU: 1 PID: 5066 Comm: syz-executor151 Not tainted 6.7.0-rc6-syzkaller-01658-gc2b2ee36250d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:hfsc_tcf_block+0x3f/0x70 net/sched/sch_hfsc.c:1265
Code: de e8 a5 2b f0 f8 48 85 db 74 2c e8 0b 30 f0 f8 e8 06 30 f0 f8 48 8d 7b 58 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 15 48 8b 43 58 5b 5d c3 e8 df 2f f0 f8 48 8d 9d d0
RSP: 0018:ffffc90003bcf408 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 000000000000fff2 RCX: ffffffff8897515b
RDX: 0000000000002009 RSI: ffffffff8897516a RDI: 000000000001004a
RBP: ffff88801675f000 R08: 0000000000000007 R09: 0000000000000000
R10: 000000000000fff2 R11: 0000000000000001 R12: ffff888023d04000
R13: ffffffff8bed5000 R14: 0000000000000001 R15: ffffffff8f19aa60
FS: 0000555555ea1380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045ad50 CR3: 000000007ae44000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
qdisc_block_add_dev net/sched/sch_api.c:1190 [inline]
qdisc_create+0x6b6/0x1430 net/sched/sch_api.c:1390
tc_modify_qdisc+0x4d5/0x1c30 net/sched/sch_api.c:1788
rtnetlink_rcv_msg+0x3c7/0xe00 net/core/rtnetlink.c:6615
netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543
netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
netlink_unicast+0x53b/0x810 net/netlink/af_netlink.c:1367
netlink_sendmsg+0x8b7/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xd5/0x180 net/socket.c:745
____sys_sendmsg+0x6ac/0x940 net/socket.c:2584
___sys_sendmsg+0x135/0x1d0 net/socket.c:2638
__sys_sendmsg+0x117/0x1e0 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f6a6284c7f9
Code: 48 83 c4 28 c3 e8 27 18 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff964096d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6a6284c7f9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007fff964096f0 R08: 00007fff96409750 R09: 00007fff96409750
R10: 00007fff96409750 R11: 0000000000000246 R12: 00007f6a628bf5f0
R13: 00007fff964098d8 R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hfsc_tcf_block+0x3f/0x70 net/sched/sch_hfsc.c:1265
Code: de e8 a5 2b f0 f8 48 85 db 74 2c e8 0b 30 f0 f8 e8 06 30 f0 f8 48 8d 7b 58 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 15 48 8b 43 58 5b 5d c3 e8 df 2f f0 f8 48 8d 9d d0
RSP: 0018:ffffc90003bcf408 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 000000000000fff2 RCX: ffffffff8897515b
RDX: 0000000000002009 RSI: ffffffff8897516a RDI: 000000000001004a
RBP: ffff88801675f000 R08: 0000000000000007 R09: 0000000000000000
R10: 000000000000fff2 R11: 0000000000000001 R12: ffff888023d04000
R13: ffffffff8bed5000 R14: 0000000000000001 R15: ffffffff8f19aa60
FS: 0000555555ea1380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dcfb61a758 CR3: 000000007ae44000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: de e8 fsubrp %st,%st(0)
2: a5 movsl %ds:(%rsi),%es:(%rdi)
3: 2b f0 sub %eax,%esi
5: f8 clc
6: 48 85 db test %rbx,%rbx
9: 74 2c je 0x37
b: e8 0b 30 f0 f8 call 0xf8f0301b
10: e8 06 30 f0 f8 call 0xf8f0301b
15: 48 8d 7b 58 lea 0x58(%rbx),%rdi
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 75 15 jne 0x45
30: 48 8b 43 58 mov 0x58(%rbx),%rax
34: 5b pop %rbx
35: 5d pop %rbp
36: c3 ret
37: e8 df 2f f0 f8 call 0xf8f0301b
3c: 48 rex.W
3d: 8d .byte 0x8d
3e: 9d popf
3f: d0 .byte 0xd0


---
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection

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#syz fix: exact-commit-title

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[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+003911...@syzkaller.appspotmail.com

Tested on:

commit: 92de776d Merge tag 'mlx5-updates-2023-12-20' of git://..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10cb54b1e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=a4e9ca8e3c104d2a
dashboard link: https://syzkaller.appspot.com/bug?extid=0039110f932d438130f9
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=15d12036e80000

Note: testing is done by a robot and is best-effort only.

[Victor Nogueira]

On 31/12/2023 08:04, syzbot wrote:
> HEAD commit: c2b2ee36250d bridge: cfm: fix enum typo in br_cc_ccm_tx_pa..
> git tree: net-next

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17a8c0f6e80000

#syz test

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: Re: [syzbot] [net?] general protection fault in hfsc_tcf_block
Author: ji...@resnulli.us

#syz test: https://github.com/jpirko/linux_mlxsw.git wip_tc_block_fix

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+003911...@syzkaller.appspotmail.com

Tested on:

commit: 866c2695 net: sched: move block device tracking into t..
git tree: https://github.com/jpirko/linux_mlxsw.git wip_tc_block_fix
console output: https://syzkaller.appspot.com/x/log.txt?x=14a03de9e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=a4e9ca8e3c104d2a
dashboard link: https://syzkaller.appspot.com/bug?extid=0039110f932d438130f9
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.