SYZFAIL: tun: can't open /dev/net/tun (2)

Status: upstream: reported syz repro on 2025/10/14 07:23
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+2036e33bb2d401ccef8d@syzkaller.appspotmail.com
First crash: 305d, last: 184d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/11/08 linux-6.1.y (ToT) f6e38ae624cf syz [report] SYZFAIL: tun: can't open /dev/net/tun
2025/11/08 upstream (ToT) e811c33b1f13 syz Didn't crash
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 SYZFAIL: tun: can't open /dev/net/tun (2) origin:lts-only -1 syz error 4 14d 281d 0/3 upstream: reported syz repro on 2025/11/07 16:34
android-5-10 SYZFAIL: tun: can't open /dev/net/tun -1 1 1742d 1742d 0/2 auto-closed as invalid on 2022/02/05 06:28
android-5-15 SYZFAIL: tun: can't open /dev/net/tun origin:upstream -1 syz error 37 6d01h 1009d 0/2 premoderation: reported syz repro on 2023/11/10 07:03
android-5-10 SYZFAIL: tun: can't open /dev/net/tun (2) -1 syz error error 82 128d 1630d 0/2 premoderation: reported syz repro on 2022/02/27 16:56
android-54 SYZFAIL: tun: can't open /dev/net/tun -1 syz 18 457d 1818d 0/2 upstream: reported syz repro on 2021/08/23 10:35
linux-4.19 SYZFAIL: tun: can't open /dev/net/tun -1 syz error 3 1629d 1771d 0/1 upstream: reported syz repro on 2021/10/09 05:44
android-6-1 SYZFAIL: tun: can't open /dev/net/tun origin:upstream -1 syz error error 39 99d 1009d 0/2 premoderation: reported syz repro on 2023/11/09 20:06
linux-5.15 SYZFAIL: tun: can't open /dev/net/tun -1 1 624d 624d 0/3 auto-obsoleted due to no activity on 2025/03/08 18:06
upstream SYZFAIL: tun: can't open /dev/net/tun -1 1 1924d 1924d 0/29 auto-closed as invalid on 2021/08/06 17:44
android-6-12 SYZFAIL: tun: can't open /dev/net/tun origin:upstream -1 syz 54 9d19h 410d 0/1 premoderation: reported syz repro on 2025/07/01 04:36
linux-6.1 SYZFAIL: tun: can't open /dev/net/tun origin:upstream -1 syz done 1 684d 989d 3/3 fixed on 2024/11/01 17:06
linux-6.6 SYZFAIL: tun: can't open /dev/net/tun origin:lts-only -1 syz error 5 218d 279d 0/2 upstream: reported syz repro on 2025/11/09 04:42
▶ ▼ Fix bisection attempts (4)
Created Duration User Patch Repo Result
2026/05/29 07:13 18m fix candidate upstream error job log
2026/03/25 17:01 7m fix candidate upstream error job log
2026/02/23 09:03 1m fix candidate upstream error job log
2026/01/23 19:07 1m fix candidate upstream error job log

Sample crash report:
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: tun: can't open /dev/net/tun
 (errno 2: No such file or directory)
loop exited with status 67
SYZFAIL: repeatedly failed to execute the program
proc=2 req=2910 state=3 status=67 (errno 32: Broken pipe)
connection error: failed to recv *flatrpc.ExecutorMessageRawT: read tcp 127.0.0.1:40911->127.0.0.1:51212: read: connection reset by peer

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/08 19:01 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2025/12/05 13:57 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2025/11/07 16:17 linux-6.1.y f6e38ae624cf 4e1406b4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2026/02/09 17:20 linux-6.1.y 0182cb5b74ee df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2025/11/25 07:51 linux-6.1.y f6e38ae624cf 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2025/10/26 02:47 linux-6.1.y 8e6e2188d949 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan SYZFAIL: tun: can't open /dev/net/tun
2026/02/12 08:02 linux-6.1.y 8ce36b2849ef 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 SYZFAIL: tun: can't open /dev/net/tun
2025/12/19 00:16 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 SYZFAIL: tun: can't open /dev/net/tun
2025/12/11 12:14 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 SYZFAIL: tun: can't open /dev/net/tun
2025/12/10 01:44 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 SYZFAIL: tun: can't open /dev/net/tun
2025/11/11 16:04 linux-6.1.y f6e38ae624cf 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 SYZFAIL: tun: can't open /dev/net/tun
2025/10/14 07:22 linux-6.1.y 882efbdd9d34 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 SYZFAIL: tun: can't open /dev/net/tun
* Struck through repros no longer work on HEAD.