memory leak in null_init_zoned_dev

Status: upstream: reported C repro on 2026/08/14 00:03
Subsystems: block
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+f57d67a92532a98a562d@syzkaller.appspotmail.com
First crash: 5d00h, last: 5d00h
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
eac9be5a assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ memory leak in null_init_zoned_dev 2026/08/09 17:24 2026/08/09 17:24 2026/08/09 17:28 5d63f80b
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] nullb: free zones when device is power-off 1 (1) 2026/08/14 08:21
[syzbot] [block?] memory leak in null_init_zoned_dev 1 (3) 2026/08/14 08:06
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/14 04:50 29m eadavis@qq.com patch upstream OK job log log

Sample crash report:
BUG: memory leak
unreferenced object 0xffff888126990000 (size 56000):
  comm "syz.0.17", pid 5947, jiffies 4294943074
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 02 00 00 00 01 00 00 00  ................
  backtrace (crc 5c9573f8):
    ___kmalloc_large_node+0xbc/0x100 mm/slub.c:5287
    __kmalloc_large_node_noprof+0x1a/0xb0 mm/slub.c:5305
    __do_kmalloc_node mm/slub.c:5322 [inline]
    __kvmalloc_node_noprof+0x460/0x6f0 mm/slub.c:6905
    null_init_zoned_dev+0x108/0x520 drivers/block/null_blk/zoned.c:94
    null_add_dev+0x8a6/0xae0 drivers/block/null_blk/main.c:1993
    nullb_device_power_store+0xf9/0x1f0 drivers/block/null_blk/main.c:501
    flush_write_buffer fs/configfs/file.c:207 [inline]
    configfs_write_iter+0x10d/0x1a0 fs/configfs/file.c:229
    new_sync_write fs/read_write.c:595 [inline]
    vfs_write+0x3ac/0x720 fs/read_write.c:687
    ksys_write+0xa5/0x170 fs/read_write.c:739
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xf8/0x610 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff888127f80000 (size 56000):
  comm "syz.0.18", pid 5951, jiffies 4294943093
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 02 00 00 00 01 00 00 00  ................
  backtrace (crc 5c9573f8):
    ___kmalloc_large_node+0xbc/0x100 mm/slub.c:5287
    __kmalloc_large_node_noprof+0x1a/0xb0 mm/slub.c:5305
    __do_kmalloc_node mm/slub.c:5322 [inline]
    __kvmalloc_node_noprof+0x460/0x6f0 mm/slub.c:6905
    null_init_zoned_dev+0x108/0x520 drivers/block/null_blk/zoned.c:94
    null_add_dev+0x8a6/0xae0 drivers/block/null_blk/main.c:1993
    nullb_device_power_store+0xf9/0x1f0 drivers/block/null_blk/main.c:501
    flush_write_buffer fs/configfs/file.c:207 [inline]
    configfs_write_iter+0x10d/0x1a0 fs/configfs/file.c:229
    new_sync_write fs/read_write.c:595 [inline]
    vfs_write+0x3ac/0x720 fs/read_write.c:687
    ksys_write+0xa5/0x170 fs/read_write.c:739
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xf8/0x610 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/09 17:14 upstream 06cf61899d64 5d63f80b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in null_init_zoned_dev
* Struck through repros no longer work on HEAD.