syzbot


WARNING: proc registration bug in unregister_irq_proc

Status: moderation: reported on 2026/01/29 11:14
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+0f4dfdeab21235b91d40@syzkaller.appspotmail.com
First crash: 7d15h, last: 7d15h

Sample crash report:
------------[ cut here ]------------
remove_proc_entry: removing non-empty directory 'irq/30', leaking at least 'eth1-rx-0'
WARNING: fs/proc/generic.c:742 at remove_proc_entry+0x4b1/0x5b0 fs/proc/generic.c:742, CPU#3: syz.7.15488/28932
Modules linked in:
CPU: 3 UID: 0 PID: 28932 Comm: syz.7.15488 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:remove_proc_entry+0x4c5/0x5b0 fs/proc/generic.c:742
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 b3 00 00 00 48 8d 3d bf 64 0e 0e 48 8b 93 d0 00 00 00 4d 89 f0 4c 89 e9 48 c7 c6 40 c2 a8 8b <67> 48 0f b9 3a e9 5a fe ff ff e8 9c 2a 57 ff 48 8d 7d 18 48 b8 00
RSP: 0000:ffffc9000c5de850 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88801c708140 RCX: ffff888049b04d5c
RDX: ffff88801c70821c RSI: ffffffff8ba8c240 RDI: ffffffff90bd8480
RBP: ffff888049b04d38 R08: ffff88806c8ca0dc R09: ffffed1009360993
R10: ffff888049b04c9b R11: 0000000000000000 R12: ffff888049b04c80
R13: ffff888049b04d5c R14: ffff88806c8ca0dc R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880976e3000(0063) knlGS:00000000f53f6b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7246d10 CR3: 000000005def7000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0400000000000e0b DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 unregister_irq_proc+0x200/0x2a0 kernel/irq/proc.c:404
 free_desc+0x8a/0x190 kernel/irq/irqdesc.c:473
 irq_free_descs+0x84/0xe0 kernel/irq/irqdesc.c:787
 irq_domain_free_irqs+0x46f/0x5c0 kernel/irq/irqdomain.c:1902
 __msi_domain_free_irqs kernel/irq/msi.c:1619 [inline]
 msi_domain_free_locked.part.0+0x524/0x6b0 kernel/irq/msi.c:1645
 msi_domain_free_locked kernel/irq/msi.c:1632 [inline]
 msi_domain_free_irqs_range_locked kernel/irq/msi.c:1668 [inline]
 msi_domain_free_irqs_all_locked+0x11d/0x170 kernel/irq/msi.c:1701
 pci_msi_teardown_msi_irqs+0xb3/0xd0 drivers/pci/msi/irqdomain.c:28
 pci_free_msi_irqs+0x1f/0xa0 drivers/pci/msi/msi.c:911
 pci_disable_msix drivers/pci/msi/api.c:200 [inline]
 pci_disable_msix+0xda/0x130 drivers/pci/msi/api.c:193
 e1000e_reset_interrupt_capability drivers/net/ethernet/intel/e1000e/netdev.c:2028 [inline]
 e1000_request_irq+0x473/0xdc0 drivers/net/ethernet/intel/e1000e/netdev.c:2164
 e1000e_open+0x471/0x1800 drivers/net/ethernet/intel/e1000e/netdev.c:4677
 __dev_open+0x3ad/0x960 net/core/dev.c:1696
 __dev_change_flags+0x558/0x6f0 net/core/dev.c:9749
 netif_change_flags+0x8d/0x160 net/core/dev.c:9812
 do_setlink.isra.0+0x1abb/0x3e50 net/core/rtnetlink.c:3158
 rtnl_group_changelink net/core/rtnetlink.c:3790 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3944 [inline]
 rtnl_newlink+0x1b79/0x2380 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
 __sys_sendmsg+0x170/0x220 net/socket.c:2678
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xde/0x660 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf73cd579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00
RSP: 002b:00000000f53f650c EFLAGS: 00000292 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000180
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	fa                   	cli
   1:	48 c1 ea 03          	shr    $0x3,%rdx
   5:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   9:	0f 85 b3 00 00 00    	jne    0xc2
   f:	48 8d 3d bf 64 0e 0e 	lea    0xe0e64bf(%rip),%rdi        # 0xe0e64d5
  16:	48 8b 93 d0 00 00 00 	mov    0xd0(%rbx),%rdx
  1d:	4d 89 f0             	mov    %r14,%r8
  20:	4c 89 e9             	mov    %r13,%rcx
  23:	48 c7 c6 40 c2 a8 8b 	mov    $0xffffffff8ba8c240,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 5a fe ff ff       	jmp    0xfffffe8e
  34:	e8 9c 2a 57 ff       	call   0xff572ad5
  39:	48 8d 7d 18          	lea    0x18(%rbp),%rdi
  3d:	48                   	rex.W
  3e:	b8                   	.byte 0xb8

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/25 11:10 upstream 5dbeeb268b63 40acda8a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING: proc registration bug in unregister_irq_proc
* Struck through repros no longer work on HEAD.