syzbot


WARNING: refcount bug in free_netdevs

Status: upstream: reported on 2022/12/09 08:33
Reported-by: syzbot+a1ed8ffe3121380cd5dd@syzkaller.appspotmail.com
Fix commit: e42f9c2e6aad RDMA: Add missed netdev_put() for the netdevice_tracker
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak 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 ci-upstream-kmsan-gce-386 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-riscv64]
First crash: 60d, last: 55d

Sample crash report:
smc: removing ib device syz1
------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 1 PID: 12966 at lib/refcount.c:31 refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31
Modules linked in:
CPU: 1 PID: 12966 Comm: kworker/u4:15 Not tainted 6.1.0-rc8-next-20221207-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: ib-unreg-wq ib_unregister_work
RIP: 0010:refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31
Code: 05 5a 60 51 0a 01 e8 35 0a b5 05 0f 0b e9 d3 fe ff ff e8 6c 9b 75 fd 48 c7 c7 c0 6d a6 8a c6 05 37 60 51 0a 01 e8 16 0a b5 05 <0f> 0b e9 b4 fe ff ff 48 89 ef e8 5a b5 c3 fd e9 5c fe ff ff 0f 1f
RSP: 0018:ffffc9001496fb30 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888094769d40 RSI: ffffffff8166b1dc RDI: fffff5200292df58
RBP: ffff888076954600 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000001 R11: 0000000000000000 R12: 1ffff9200292df6b
R13: 0000000000000000 R14: ffff888076954600 R15: ffff888020a60000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efd7856e000 CR3: 000000007ddcc000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 ref_tracker_free+0x539/0x6b0 lib/ref_tracker.c:118
 netdev_tracker_free include/linux/netdevice.h:4039 [inline]
 netdev_put include/linux/netdevice.h:4056 [inline]
 dev_put include/linux/netdevice.h:4082 [inline]
 free_netdevs+0x1f8/0x470 drivers/infiniband/core/device.c:2204
 __ib_unregister_device+0xa0/0x1a0 drivers/infiniband/core/device.c:1478
 ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1586
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-upstream-linux-next-kasan-gce-root 2022/12/12 23:07 linux-next 591cd61541b9 67be1ae7 .config console log report info [disk image] [vmlinux] [kernel image] WARNING: refcount bug in free_netdevs
ci-upstream-linux-next-kasan-gce-root 2022/12/11 04:54 linux-next 591cd61541b9 67be1ae7 .config console log report info [disk image] [vmlinux] [kernel image] WARNING: refcount bug in free_netdevs
ci-upstream-linux-next-kasan-gce-root 2022/12/08 11:48 linux-next 591cd61541b9 1034e5fa .config console log report info [disk image] [vmlinux] [kernel image] WARNING: refcount bug in free_netdevs
* Struck through repros no longer work on HEAD.