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

Status: upstream: reported syz repro on 2025/11/07 16:34
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+3730c68ed0e9291dbcdb@syzkaller.appspotmail.com
First crash: 259d, last: 33d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/11/07 linux-5.15.y (ToT) cc5ec8769306 syz [report] SYZFAIL: tun: can't open /dev/net/tun
2025/11/07 upstream (ToT) da32d155f4a8 syz Didn't crash
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 SYZFAIL: tun: can't open /dev/net/tun (2) origin:lts-only -1 syz error 12 162d 283d 0/3 upstream: reported syz repro on 2025/10/14 07:23
android-5-10 SYZFAIL: tun: can't open /dev/net/tun -1 1 1720d 1720d 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 88d 987d 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 106d 1608d 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 435d 1796d 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 1607d 1749d 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 77d 987d 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 602d 602d 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 1903d 1903d 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 94d 388d 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 662d 967d 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 197d 257d 0/2 upstream: reported syz repro on 2025/11/09 04:42
▶ ▼ Last patch testing requests (9)
Created Duration User Patch Repo Result
2026/06/21 10:19 14m retest repro linux-5.15.y report log
2026/06/21 10:19 15m retest repro linux-5.15.y report log
2026/05/11 01:00 20m retest repro linux-5.15.y report log
2026/04/02 19:26 16m retest repro linux-5.15.y report log
2026/04/02 19:26 11m retest repro linux-5.15.y report log
2026/02/28 17:43 32m retest repro linux-5.15.y report log
2026/01/22 18:49 15m retest repro linux-5.15.y report log
2026/01/22 18:49 11m retest repro linux-5.15.y report log
2025/12/20 15:54 11m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (5)
Created Duration User Patch Repo Result
2026/05/10 15:20 15m fix candidate upstream error job log
2026/03/25 10:12 48m fix candidate upstream error job log
2026/02/23 06:54 1m fix candidate upstream error job log
2026/01/24 05:15 1m fix candidate upstream error job log
2025/11/18 21:32 0m fix candidate upstream error

Sample crash report:
2026/01/08 17:25:15 executed programs: 4133
2026/01/08 17:25:20 executed programs: 4219
2026/01/08 17:25:26 executed programs: 4285
2026/01/08 17:25:31 executed programs: 4370
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=1 req=3716 state=3 status=67 (errno 32: Broken pipe)
connection error: failed to recv *flatrpc.ExecutorMessageRawT: read tcp 127.0.0.1:45971->127.0.0.1:35566: read: connection reset by peer

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/08 17:25 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2025/12/05 14:41 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2025/11/07 16:33 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf SYZFAIL: tun: can't open /dev/net/tun
2025/12/21 09:49 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan SYZFAIL: tun: can't open /dev/net/tun
* Struck through repros no longer work on HEAD.