syzbot


general protection fault in fib_table_flush

Status: closed as invalid on 2025/09/12 08:55
Subsystems: net
[Documentation on labels]
First crash: 57d, last: 52d

Sample crash report:
bond0: (slave dummy0): Releasing backup interface
dummy0: left allmulticast mode
Oops: general protection fault, probably for non-canonical address 0xdffffc001fffe000: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x00000000ffff0000-0x00000000ffff0007]
CPU: 0 UID: 0 PID: 15770 Comm: syz.2.2768 Not tainted 6.17.0-rc1-syzkaller-00127-g715c7a36d59f #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:fib_table_flush+0x29f/0x11a0 net/ipv4/fib_trie.c:2038
Code: 44 89 e7 44 89 f6 e8 b0 7d b7 f7 45 38 f4 76 6e e8 26 7d b7 f7 48 89 df e8 be d1 ff ff eb 64 4d 8d 75 05 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 28 0d 00 00 45 0f b6 36 31 ff 44 89 f6
RSP: 0018:ffffc9001c9ee500 EFLAGS: 00010207
RAX: 000000001fffe000 RBX: ffff8880579b5c20 RCX: 0000000000080000
RDX: ffffc9000da72000 RSI: 00000000000267e9 RDI: 00000000000267ea
RBP: ffffc9001c9ee6d8 R08: ffffffff8fa37e37 R09: 1ffffffff1f46fc6
R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: dffffc0000000000
R13: 00000000ffff0000 R14: 00000000ffff0005 R15: 0000000000000001
FS:  00007f28c4a946c0(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2d64b1 CR3: 0000000074606000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 fib_flush net/ipv4/fib_frontend.c:195 [inline]
 fib_disable_ip+0xfd/0x170 net/ipv4/fib_frontend.c:1455
 fib_netdev_event+0x318/0x490 net/ipv4/fib_frontend.c:-1
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 netif_close_many+0x29c/0x410 net/core/dev.c:1784
 netif_close+0x158/0x210 net/core/dev.c:1797
 dev_close+0x10a/0x220 net/core/dev_api.c:220
 __bond_release_one+0xbb5/0x10e0 drivers/net/bonding/bond_main.c:2657
 do_set_master+0x312/0x6d0 net/core/rtnetlink.c:2932
 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3150
 rtnl_group_changelink net/core/rtnetlink.c:3775 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3929 [inline]
 rtnl_newlink+0x149f/0x1c70 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 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: 0033:0x7f28c3b8ebe9
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:00007f28c4a94038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f28c3db6090 RCX: 00007f28c3b8ebe9
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000003
RBP: 00007f28c3c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f28c3db6128 R14: 00007f28c3db6090 R15: 00007ffdbf845928
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:fib_table_flush+0x29f/0x11a0 net/ipv4/fib_trie.c:2038
Code: 44 89 e7 44 89 f6 e8 b0 7d b7 f7 45 38 f4 76 6e e8 26 7d b7 f7 48 89 df e8 be d1 ff ff eb 64 4d 8d 75 05 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 28 0d 00 00 45 0f b6 36 31 ff 44 89 f6
RSP: 0018:ffffc9001c9ee500 EFLAGS: 00010207
RAX: 000000001fffe000 RBX: ffff8880579b5c20 RCX: 0000000000080000
RDX: ffffc9000da72000 RSI: 00000000000267e9 RDI: 00000000000267ea
RBP: ffffc9001c9ee6d8 R08: ffffffff8fa37e37 R09: 1ffffffff1f46fc6
R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: dffffc0000000000
R13: 00000000ffff0000 R14: 00000000ffff0005 R15: 0000000000000001
FS:  00007f28c4a946c0(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c24bd5e CR3: 0000000074606000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	44 89 e7             	mov    %r12d,%edi
   3:	44 89 f6             	mov    %r14d,%esi
   6:	e8 b0 7d b7 f7       	call   0xf7b77dbb
   b:	45 38 f4             	cmp    %r14b,%r12b
   e:	76 6e                	jbe    0x7e
  10:	e8 26 7d b7 f7       	call   0xf7b77d3b
  15:	48 89 df             	mov    %rbx,%rdi
  18:	e8 be d1 ff ff       	call   0xffffd1db
  1d:	eb 64                	jmp    0x83
  1f:	4d 8d 75 05          	lea    0x5(%r13),%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 28 0d 00 00    	jne    0xd5f
  37:	45 0f b6 36          	movzbl (%r14),%r14d
  3b:	31 ff                	xor    %edi,%edi
  3d:	44 89 f6             	mov    %r14d,%esi

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/18 17:00 net 715c7a36d59f 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in fib_table_flush
2025/08/17 04:47 net-next bab3ce404553 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce general protection fault in fib_table_flush
2025/08/12 22:58 net-next f8262b8dadfa c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce general protection fault in fib_table_flush
* Struck through repros no longer work on HEAD.