syzbot
WARNING in blk_mq_alloc_tag_set
Status:
upstream: reported on 2026/07/28 12:58
Subsystems:
block
Labels:
prio:high
[Documentation on labels]
Reported-by: syzbot+18431bc7dccedc61778f@syzkaller.appspotmail.com
First crash: 53d, last: 20h05m
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Last patch testing requests (1)
Sample crash report:
nvme nvme43: creating 2 I/O queues.
blk-mq: failed to allocate request map
------------[ cut here ]------------
timer_delete_sync(&sdp->delay_work) && rcu_segcblist_n_cbs(&sdp->srcu_cblist)
WARNING: kernel/rcu/srcutree.c:706 at cleanup_srcu_struct+0x6e4/0xb30 kernel/rcu/srcutree.c:706, CPU#0: syz.7.831/9310
Modules linked in:
CPU: 0 UID: 0 PID: 9310 Comm: syz.7.831 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:cleanup_srcu_struct+0x6e4/0xb30 kernel/rcu/srcutree.c:706
Code: 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 f4 03 00 00 48 8b 83 e8 00 00 00 48 8d 93 80 01 00 00 48 85 c0 0f 84 a7 fc ff ff 90 <0f> 0b 90 48 8d 8b 00 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 89
RSP: 0018:ffffc9000504f9c8 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffffe8ffffcf5000 RCX: ffffc900103f1000
RDX: ffffe8ffffcf5180 RSI: ffffffff81f6de5f RDI: ffff88802a112580
RBP: ffff8880560ad000 R08: 0000000000000005 R09: 00000000ffffffff
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88802be2c310
R13: 0000000000000000 R14: ffffffff8e6580b0 R15: ffff88802be2c350
FS: 00007f1c893946c0(0000) GS:ffff888123b59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32a18ff8 CR3: 000000007a316000 CR4: 00000000003526f0
Call Trace:
<TASK>
blk_mq_alloc_tag_set+0xdd8/0x1330 block/blk-mq.c:4928
nvme_alloc_io_tag_set+0x3bc/0x750 drivers/nvme/host/core.c:5068
nvme_loop_create_io_queues drivers/nvme/target/loop.c:515 [inline]
nvme_loop_create_ctrl+0x6bc/0xee0 drivers/nvme/target/loop.c:610
nvmf_create_ctrl drivers/nvme/host/fabrics.c:1361 [inline]
nvmf_dev_write+0x4ee/0xb60 drivers/nvme/host/fabrics.c:1408
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c8859e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1c89394028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1c88826180 RCX: 00007f1c8859e159
RDX: 0000000000000017 RSI: 0000200000000640 RDI: 0000000000000003
RBP: 00007f1c8863503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1c88826218 R14: 00007f1c88826180 R15: 00007ffc4cb96d58
</TASK>
* Struck through repros no longer work on HEAD.