WARNING in nvmet_fc_register_targetport

Status: upstream: reported C repro on 2026/08/12 00:13
Subsystems: nvme
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+18b6b27f58e98c240814@syzkaller.appspotmail.com
Fix commit: nvmet-fc: fix invalid free in LS IOD error path
Patched on: [ci-upstream-linux-next-kasan-gce-root], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 9d23h, last: 4d11h
▶ ▼ ✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision
e4d14228 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in nvmet_fc_register_targetport 2026/08/14 00:45 2026/08/14 00:45 2026/08/14 00:47 0165196a
4cc56b50 repro-c Reproduced: ✅ ❓ WARNING in nvmet_fc_register_targetport 2026/08/12 14:24 2026/08/12 14:55 2026/08/12 15:38 a56bc0a5
f8cd8ff3 assessment-security 💥 WARNING in nvmet_fc_register_targetport 2026/08/11 00:56 2026/08/11 00:56 2026/08/11 00:56 039457bd
0ea2bfd5 assessment-security 💥 WARNING in nvmet_fc_register_targetport 2026/08/09 02:18 2026/08/09 02:18 2026/08/09 02:18 5d63f80b
▶ ▼ Duplicate bugs (1)
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
KASAN: invalid-free in nvmet_fc_alloc_ls_iodlist nvme prio:high 24 2 2d20h 7d20h 0/29 closed as dup on 2026/08/12 16:57
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [nvme?] WARNING in nvmet_fc_register_targetport 1 (3) 2026/08/13 08:42
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/13 07:49 19m nogikh@google.com upstream report job log log

Sample crash report:
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 00007fe0eeb9c063 R14: 00007fe0eebc6cc0 R15: 0000000000000002
 </TASK>
------------[ cut here ]------------
!PageLargeKmalloc(page)
WARNING: mm/slub.c:6602 at free_large_kmalloc+0xbf/0x100 mm/slub.c:6602, CPU#2: syz-executor838/6035
Modules linked in:
CPU: 2 UID: 0 PID: 6035 Comm: syz-executor838 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:free_large_kmalloc+0xbf/0x100 mm/slub.c:6602
Code: 28 90 0f 0b 90 80 3d f7 c8 9a 0e 00 0f 84 87 b4 b5 fe 48 8b 74 24 28 48 89 ef e8 8c 3b 0c 00 b8 00 f0 ff ff 45 31 ed eb 9d 90 <0f> 0b 90 48 83 c4 08 48 89 df 48 c7 c6 53 4d 19 8e 5b 5d 41 5c 41
RSP: 0018:ffffc9000347fa28 EFLAGS: 00010202
RAX: 00000000000000ff RBX: ffffea00016377c0 RCX: 000000000000002e
RDX: 0000000000000000 RSI: ffff888058ddff20 RDI: ffffea00016377c0
RBP: ffff888058ddff20 R08: ffff888052911000 R09: 00000000ffffffff
R10: ffffffffffffffff R11: 0000000000000000 R12: 00000000ffffffff
R13: 1ffff9200068ff5e R14: dead000000000122 R15: ffff888058ddff30
FS:  000055557f333400(0000) GS:ffff8880d5fec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557f335768 CR3: 0000000058747000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nvmet_fc_alloc_ls_iodlist drivers/nvme/target/fc.c:569 [inline]
 nvmet_fc_register_targetport+0x114c/0x1c30 drivers/nvme/target/fc.c:1411
 fcloop_create_target_port+0x156/0x5a0 drivers/nvme/target/fcloop.c:1558
 dev_attr_store+0x58/0x80 drivers/base/core.c:2505
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe0eeb63277
Code: 48 89 fa 4c 89 df e8 98 1d 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffdd23d920 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055557f333400 RCX: 00007fe0eeb63277
RDX: 000000000000002f RSI: 00007fffdd23d970 RDI: 0000000000000003
RBP: 00007fffdd23d970 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 00007fe0eeb9c063 R14: 00007fe0eebc6cc0 R15: 0000000000000002
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/13 08:41 upstream 3d6d817622b0 e4ef95d6 .config console log report C ci-qemu-upstream WARNING in nvmet_fc_register_targetport
2026/08/07 21:30 upstream f9a2394a2348 e4ef95d6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in nvmet_fc_register_targetport
* Struck through repros no longer work on HEAD.