syzbot


general protection fault in em_u32_match (2)

Status: upstream: reported C repro on 2023/01/14 00:52
Reported-by: syzbot+b13ecef30148e3980463@syzkaller.appspotmail.com
First crash: 690d, last: 690d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in em_u32_match net 1 1582d 1582d 0/28 auto-closed as invalid on 2020/11/02 22:53
linux-4.19 general protection fault in em_u32_match 1 1191d 1191d 0/1 auto-closed as invalid on 2021/12/29 15:06
linux-4.14 general protection fault in em_u32_match C 1 665d 696d 0/1 upstream: reported C repro on 2023/01/08 12:41
upstream BUG: unable to handle kernel NULL pointer dereference in em_u32_match net C 2 704d 760d 22/28 fixed on 2023/02/24 13:50

Sample crash report:
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: 1 PID: 8301 Comm: kworker/1:3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:em_u32_match+0x156/0x300 net/sched/em_u32.c:33
Code: 9c 01 00 00 41 23 5c 24 0c 48 63 db 4c 01 fb e8 40 da c2 fa 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 21
RSP: 0018:ffff888094fe6bc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880b3b11cde RCX: ffffffff869f8a05
RDX: 0000000000000001 RSI: ffffffff869fab30 RDI: 0000000000000008
RBP: ffff8880ab743c00 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880b3b11cc0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd308274f8 CR3: 0000000009e6d000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tcf_em_match net/sched/ematch.c:496 [inline]
 __tcf_em_tree_match+0x14a/0x530 net/sched/ematch.c:522
 tcf_em_tree_match include/net/pkt_cls.h:531 [inline]
 basic_classify+0x1c0/0x2b0 net/sched/cls_basic.c:49
 tcf_classify+0x120/0x3c0 net/sched/cls_api.c:979
 prio_classify net/sched/sch_prio.c:46 [inline]
 prio_enqueue+0x3bb/0x7a0 net/sched/sch_prio.c:78
 __dev_xmit_skb net/core/dev.c:3494 [inline]
 __dev_queue_xmit+0x140a/0x2e00 net/core/dev.c:3807
 neigh_hh_output include/net/neighbour.h:491 [inline]
 neigh_output include/net/neighbour.h:499 [inline]
 ip_finish_output2+0xb6d/0x15a0 net/ipv4/ip_output.c:230
 ip_finish_output+0xae9/0x10b0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x203/0x5f0 net/ipv4/ip_output.c:406
 dst_output include/net/dst.h:455 [inline]
 ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125
 iptunnel_xmit+0x63b/0x9d0 net/ipv4/ip_tunnel_core.c:91
 geneve_xmit_skb drivers/net/geneve.c:867 [inline]
 geneve_xmit+0x120d/0x2e60 drivers/net/geneve.c:943
 __netdev_start_xmit include/linux/netdevice.h:4349 [inline]
 netdev_start_xmit include/linux/netdevice.h:4363 [inline]
 xmit_one net/core/dev.c:3256 [inline]
 dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272
 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
 neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374
 neigh_output include/net/neighbour.h:501 [inline]
 ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x89b/0x10f0 net/ipv6/ip6_output.c:192
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip6_output+0x205/0x770 net/ipv6/ip6_output.c:209
 dst_output include/net/dst.h:455 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ndisc_send_skb+0xa24/0x1720 net/ipv6/ndisc.c:491
 ndisc_send_ns+0x51d/0x840 net/ipv6/ndisc.c:633
 addrconf_dad_work+0xb0e/0x10a0 net/ipv6/addrconf.c:4076
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace 4a630fdc4567183b ]---
RIP: 0010:em_u32_match+0x156/0x300 net/sched/em_u32.c:33
Code: 9c 01 00 00 41 23 5c 24 0c 48 63 db 4c 01 fb e8 40 da c2 fa 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 21
RSP: 0018:ffff888094fe6bc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880b3b11cde RCX: ffffffff869f8a05
RDX: 0000000000000001 RSI: ffffffff869fab30 RDI: 0000000000000008
RBP: ffff8880ab743c00 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880b3b11cc0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd308274f8 CR3: 0000000009e6d000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	9c                   	pushfq
   1:	01 00                	add    %eax,(%rax)
   3:	00 41 23             	add    %al,0x23(%rcx)
   6:	5c                   	pop    %rsp
   7:	24 0c                	and    $0xc,%al
   9:	48 63 db             	movslq %ebx,%rbx
   c:	4c 01 fb             	add    %r15,%rbx
   f:	e8 40 da c2 fa       	callq  0xfac2da54
  14:	49 8d 7c 24 08       	lea    0x8(%r12),%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:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx <-- trapping instruction
  2e:	48 89 f8             	mov    %rdi,%rax
  31:	83 e0 07             	and    $0x7,%eax
  34:	83 c0 03             	add    $0x3,%eax
  37:	38 d0                	cmp    %dl,%al
  39:	7c 08                	jl     0x43
  3b:	84 d2                	test   %dl,%dl
  3d:	0f                   	.byte 0xf
  3e:	85 21                	test   %esp,(%rcx)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/14 00:52 linux-4.19.y 3f8a27f9e27b 529798b0 .config console log report syz C [disk image] [vmlinux] ci2-linux-4-19 general protection fault in em_u32_match
* Struck through repros no longer work on HEAD.