syzbot


general protection fault in dev_get_by_name_rcu

Status: closed as invalid on 2025/09/19 09:44
Subsystems: net
[Documentation on labels]
First crash: 52d, last: 52d

Sample crash report:
IPVS: set_ctl: invalid protocol: 108 0.0.0.0:20000
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 24557 Comm: syz.4.5275 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:strcmp+0x24/0xc0 lib/string.c:283
Code: 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 54 53 48 bb 00 00 00 00 00 fc ff df 45 31 f6 4a 8d 04 37 48 89 c1 48 c1 e9 03 <0f> b6 0c 19 84 c9 75 2c 42 0f b6 2c 37 4a 8d 04 36 48 89 c1 48 c1
RSP: 0018:ffffc90003fffbf0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffc90003fffd00 RDI: 0000000000000000
RBP: 000000008bd7f493 R08: 0000000000000000 R09: ffffffff89725581
R10: 00000000000089b1 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc90003fffd50 R14: 0000000000000000 R15: ffff888028747228
FS:  00007f2612f426c0(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2e1f3d CR3: 000000003bc72000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 netdev_name_node_lookup_rcu net/core/dev.c:327 [inline]
 dev_get_by_name_rcu+0xcc/0x140 net/core/dev.c:885
 dev_load+0xc7/0x1f0 net/core/dev_ioctl.c:677
 dev_ioctl+0x680/0x1150 net/core/dev_ioctl.c:749
 sock_do_ioctl+0x22c/0x300 net/socket.c:1252
 sock_ioctl+0x576/0x790 net/socket.c:1359
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f261218ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2612f42038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f26123b5fa0 RCX: 00007f261218ebe9
RDX: 0000200000000840 RSI: 0000000000008933 RDI: 0000000000000005
RBP: 00007f2612211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f26123b6038 R14: 00007f26123b5fa0 R15: 00007fff1a90fb28
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:strcmp+0x24/0xc0 lib/string.c:283
Code: 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 54 53 48 bb 00 00 00 00 00 fc ff df 45 31 f6 4a 8d 04 37 48 89 c1 48 c1 e9 03 <0f> b6 0c 19 84 c9 75 2c 42 0f b6 2c 37 4a 8d 04 36 48 89 c1 48 c1
RSP: 0018:ffffc90003fffbf0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffc90003fffd00 RDI: 0000000000000000
RBP: 000000008bd7f493 R08: 0000000000000000 R09: ffffffff89725581
R10: 00000000000089b1 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc90003fffd50 R14: 0000000000000000 R15: ffff888028747228
FS:  00007f2612f426c0(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7c86d0fe9c CR3: 000000003bc72000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	f3 0f 1e fa          	endbr64
   a:	55                   	push   %rbp
   b:	41 57                	push   %r15
   d:	41 56                	push   %r14
   f:	41 54                	push   %r12
  11:	53                   	push   %rbx
  12:	48 bb 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbx
  19:	fc ff df
  1c:	45 31 f6             	xor    %r14d,%r14d
  1f:	4a 8d 04 37          	lea    (%rdi,%r14,1),%rax
  23:	48 89 c1             	mov    %rax,%rcx
  26:	48 c1 e9 03          	shr    $0x3,%rcx
* 2a:	0f b6 0c 19          	movzbl (%rcx,%rbx,1),%ecx <-- trapping instruction
  2e:	84 c9                	test   %cl,%cl
  30:	75 2c                	jne    0x5e
  32:	42 0f b6 2c 37       	movzbl (%rdi,%r14,1),%ebp
  37:	4a 8d 04 36          	lea    (%rsi,%r14,1),%rax
  3b:	48 89 c1             	mov    %rax,%rcx
  3e:	48                   	rex.W
  3f:	c1                   	.byte 0xc1

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/20 03:35 net-next 51992f99f068 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce general protection fault in dev_get_by_name_rcu
* Struck through repros no longer work on HEAD.