syzbot


WARNING in ip_rt_bug (3)

Status: upstream: reported C repro on 2026/05/19 20:00
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+c13a57c2639c2c0d03a6@syzkaller.appspotmail.com
First crash: 12d, last: 43m
Cause bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH net] ipv4: icmp: reject broadcast/multicast routes 2 (2) 2026/05/19 22:30
[syzbot] [net?] WARNING in ip_rt_bug (3) 0 (1) 2026/05/19 20:00
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 WARNING in ip_rt_bug -1 C error 2 1689d 2237d 0/1 upstream: reported C repro on 2020/04/03 11:53
linux-4.14 WARNING in ip_rt_bug -1 C inconclusive 1 2165d 2225d 0/1 upstream: reported C repro on 2020/04/15 03:43
linux-6.1 WARNING in ip_rt_bug (2) -1 1 775d 775d 0/3 auto-obsoleted due to no activity on 2024/07/13 04:22
linux-6.1 WARNING in ip_rt_bug -1 1 1006d 1006d 0/3 auto-obsoleted due to no activity on 2023/11/25 06:32
upstream WARNING in ip_rt_bug (2) net -1 C done error 612 13d 1315d 29/29 fixed on 2026/05/06 16:40
linux-5.15 WARNING in ip_rt_bug -1 7 379d 499d 0/3 auto-obsoleted due to no activity on 2025/08/13 17:11
linux-6.6 WARNING in ip_rt_bug -1 1 145d 145d 0/2 auto-obsoleted due to no activity on 2026/04/04 15:30
upstream WARNING in ip_rt_bug net -1 1 2970d 2962d 0/29 auto-closed as invalid on 2019/02/22 10:34
linux-6.1 WARNING in ip_rt_bug (4) origin:lts-only -1 C error 5 45d 253d 0/3 upstream: reported C repro on 2025/09/08 02:20
linux-6.1 WARNING in ip_rt_bug (3) -1 26 347d 515d 0/3 auto-obsoleted due to no activity on 2025/09/07 04:48

Sample crash report:
------------[ cut here ]------------
1
WARNING: net/ipv4/route.c:1275 at ip_rt_bug+0x2d/0x140 net/ipv4/route.c:1275, CPU#1: syz.0.17/5858
Modules linked in:
CPU: 1 UID: 0 PID: 5858 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ip_rt_bug+0x2d/0x140 net/ipv4/route.c:1275
Code: fa 55 41 57 41 56 41 55 41 54 53 48 89 d3 e8 0a fb b8 f7 66 90 e8 03 fb b8 f7 31 ff 48 89 de ba 02 00 00 00 e8 84 81 68 ff 90 <0f> 0b 90 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d e9 0f d3 9e 01 cc 49
RSP: 0018:ffffc900032ef1c0 EFLAGS: 00010286
RAX: f1fcc608b0941b00 RBX: ffff8880750b3000 RCX: 0000000080000401
RDX: 0000000000000002 RSI: ffffffff8dfa6610 RDI: ffffffff8c28ade0
RBP: ffffc900032ef4c0 R08: ffffffff9030adf7 R09: 1ffffffff20615be
R10: dffffc0000000000 R11: fffffbfff20615bf R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880750b3000 R15: dffffc0000000000
FS:  0000555579ced500(0000) GS:ffff88812538d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbd90672700 CR3: 0000000072438000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ip_send_skb net/ipv4/ip_output.c:1510 [inline]
 ip_push_pending_frames+0x8b/0x110 net/ipv4/ip_output.c:1530
 __icmp_send+0x11e4/0x1690 net/ipv4/icmp.c:1000
 icmp_send include/net/icmp.h:43 [inline]
 ip_options_compile+0x80/0xb0 net/ipv4/ip_options.c:473
 ip_rcv_options net/ipv4/ip_input.c:290 [inline]
 ip_rcv_finish_core+0xaa2/0x1c00 net/ipv4/ip_input.c:430
 ip_rcv_finish+0x14c/0x2a0 net/ipv4/ip_input.c:490
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
 __netif_receive_skb_one_core net/core/dev.c:6202 [inline]
 __netif_receive_skb net/core/dev.c:6315 [inline]
 netif_receive_skb_internal net/core/dev.c:6401 [inline]
 netif_receive_skb+0x45b/0xbf0 net/core/dev.c:6460
 tun_rx_batched+0x1de/0x790 drivers/net/tun.c:1487
 tun_get_user+0x2bbc/0x43e0 drivers/net/tun.c:1955
 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:2001
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:688
 ksys_write+0x150/0x270 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd9075d60e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffcba496af8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555579ced500 RCX: 00007fbd9075d60e
RDX: 0000000000000046 RSI: 0000200000000400 RDI: 00000000000000c8
RBP: 00007fbd90832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbd90a15fac R14: 00007fbd90a15fa0 R15: 00007fbd90a15fa0
 </TASK>

Crashes (49):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/08 11:04 net fcee7d82f27d 5633175a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/08 12:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5cbb61bf4168 5633175a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in ip_rt_bug
2026/05/20 00:57 upstream 27fa82620cba 0909d65f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ip_rt_bug
2026/05/19 13:41 upstream ab5fce87a778 223544dc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ip_rt_bug
2026/05/17 09:54 upstream 6916d5703ddf de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in ip_rt_bug
2026/05/12 02:53 upstream 50897c955902 d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in ip_rt_bug
2026/05/11 07:39 upstream 5d6919055dec 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ip_rt_bug
2026/05/10 09:17 upstream 1bfaee9d3351 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in ip_rt_bug
2026/05/12 07:35 upstream 50897c955902 07aeade5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in ip_rt_bug
2026/05/19 21:52 upstream 27fa82620cba 6cd1a940 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/18 21:49 upstream 4d3a2a466b8d 9f74d399 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/13 23:26 upstream e1914add2799 6ccb967e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/13 10:32 upstream 1d5dcaa3bd65 bc4126d8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/12 19:14 upstream c21b90f77687 a0949470 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/12 18:03 upstream c21b90f77687 07aeade5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/12 07:11 upstream 50897c955902 07aeade5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/11 18:59 upstream 5d6919055dec d168f260 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/11 07:22 upstream 5d6919055dec 845acb1c .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ip_rt_bug
2026/05/18 08:13 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/18 06:45 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/17 22:29 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/17 15:45 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/17 13:16 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/17 05:11 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/17 02:37 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/17 00:00 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/16 22:46 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/16 22:19 net aaec7096f996 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/12 17:33 net be48e5fe51a5 d5b1a17d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/11 23:05 net a450063ef86b d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/11 12:29 net a450063ef86b e6eb7c0b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/11 11:02 net a450063ef86b e6eb7c0b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/11 10:36 net a450063ef86b e6eb7c0b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/11 07:23 net a450063ef86b 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/11 05:25 net 46e9b0224475 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/10 22:31 net 46e9b0224475 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/08 15:13 net fcee7d82f27d 5633175a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/08 11:09 net fcee7d82f27d 5633175a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/08 08:40 net fcee7d82f27d 5633175a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/07 22:27 net 41ae14071cd7 e358bca5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/07 21:02 net 41ae14071cd7 e358bca5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/07 10:09 net b266bacba796 f250db59 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/07 08:25 net b266bacba796 f250db59 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip_rt_bug
2026/05/18 11:03 net-next 627ac78f2741 55156e84 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in ip_rt_bug
2026/05/18 04:26 net-next 627ac78f2741 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in ip_rt_bug
2026/05/17 01:22 net-next 627ac78f2741 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in ip_rt_bug
2026/05/11 09:34 net-next 63751099502d e6eb7c0b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in ip_rt_bug
2026/05/10 13:41 net-next 8b2feced65cd 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in ip_rt_bug
* Struck through repros no longer work on HEAD.