<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/nvme, branch v5.15.219</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.15.219</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v5.15.219'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-08-27T12:28:21+00:00</updated>
<entry>
<title>nvmet-tcp: Do not WARN on remotely-controlled oversized SGL allocations</title>
<updated>2026-08-27T12:28:21+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2026-07-27T20:03:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7b6a54d4e7b0da423c2b53ed293fd36b16c0b19e'/>
<id>urn:sha1:7b6a54d4e7b0da423c2b53ed293fd36b16c0b19e</id>
<content type='text'>
commit 737a3b535247226f6e1a7988fd9d6e63e7d6fc71 upstream.

When fuzzing the nvme target code, I tripped a kernel warning in
nvmet_tcp_map_data() because the length passed into the allocator is
controlled by the remote initiator.

A remote initiator that sends a command with an SGL claiming a huge
number, can create a scatterlist and iovec allocation of over 1 million
entries, which causes the backing kmalloc call to exceed MAX_PAGE_ORDER
and then the page allocator will trip on a WARN_ON_ONCE_GFP() message:

  WARNING: mm/page_alloc.c:5280 __alloc_frozen_pages_noprof
  Workqueue: nvmet_tcp_wq nvmet_tcp_io_work
  ...
  sgl_alloc_order
  nvmet_tcp_map_data
  nvmet_tcp_try_recv_pdu

As it's never good to trip a kernel warning remotely due to many systems
having panic-on-warn enabled, let's silence it by just add GFP_NOWARN to
the allocation flags.

Assisted-by: gkh_clanker_2000
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>nvmet-fc: fix invalid free in LS IOD error path</title>
<updated>2026-08-27T12:28:21+00:00</updated>
<author>
<name>Jiang HongHui</name>
<email>jiang_hh2019@163.com</email>
</author>
<published>2026-07-29T11:02:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=449e9c4f8db84ad9d9bb288029b230bcf590faa2'/>
<id>urn:sha1:449e9c4f8db84ad9d9bb288029b230bcf590faa2</id>
<content type='text'>
commit ba98d6796d12258e837ece065d2ecb59d76ce4ff upstream.

nvmet_fc_alloc_ls_iodlist() advances iod while initializing the LS IOD
array. If an rqstbuf allocation or response buffer DMA mapping fails,
the unwind loop decrements iod past the start of the array. The final
kfree(iod) therefore frees an address before the allocated object.

This can be reproduced with nvme-fcloop and failslab by setting
fail-nth to 6 before creating a target port. KASAN reports:

  BUG: KASAN: invalid-free in nvmet_fc_register_targetport
  Free of addr ffff88816cf8ff48 by task nvmet_fail_nth/9552

Free the original allocation base stored in tgtport-&gt;iod instead. With
this fix applied, the same sysfs write with fail-nth=6 returns -ENOMEM
without any KASAN report.

Fixes: c53432030d86 ("nvme-fabrics: Add target support for FC transport")
Cc: stable@vger.kernel.org
Reviewed-by: Maurizio Lombardi &lt;mlombard@redhat.com&gt;
Assisted-by: Codex:gpt-5
Signed-off-by: Jiang HongHui &lt;jiang_hh2019@163.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>nvmet-tcp: Fix potential UAF when ddgst mismatch</title>
<updated>2026-08-19T15:13:51+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2026-07-21T13:54:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7e558308eba14c8136cb1e615f0c850f76d1fc0a'/>
<id>urn:sha1:7e558308eba14c8136cb1e615f0c850f76d1fc0a</id>
<content type='text'>
commit dbbd07d0a7020b80f6a7028e561908f7b83b3d5a upstream.

Shivam Kumar found via vulnerability testing:
When data digest is enabled on an NVMe/TCP connection and a digest
mismatch occurs on a non-final H2C_DATA PDU during an R2T-based
data transfer, the digest error handler in nvmet_tcp_try_recv_ddgst()
calls nvmet_req_uninit() - which performs percpu_ref_put() on the
submission queue - but does NOT mark the command as completed. It
does not set cqe-&gt;status, does not modify rbytes_done, and does not
clear any flag. When the subsequent fatal error triggers queue
teardown, nvmet_tcp_uninit_data_in_cmds() iterates all commands,
checks nvmet_tcp_need_data_in() for each one, and finds that the
already-uninited command still appears to need data (because
rbytes_done &lt; transfer_len and cqe-&gt;status == 0). It therefore calls
nvmet_req_uninit() a second time on the same command - a double
percpu_ref_put against a single percpu_ref_get.

Reported-by: Shivam Kumar &lt;kumar.shivam43666@gmail.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Shivam Kumar &lt;kumar.shivam43666@gmail.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path</title>
<updated>2026-07-24T13:51:53+00:00</updated>
<author>
<name>Shivam Kumar</name>
<email>kumar.shivam43666@gmail.com</email>
</author>
<published>2026-07-20T13:45:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e'/>
<id>urn:sha1:ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e</id>
<content type='text'>
commit 4606467a75cfc16721937272ed29462a750b60c8 upstream.

In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected,
nvmet_req_uninit() is called unconditionally. However, if the command
arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init()
had returned false and percpu_ref_tryget_live() was never executed. The
unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a
refcount underflow, leading to a WARNING in
percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and
eventually a permanent workqueue deadlock.

Check cmd-&gt;flags &amp; NVMET_TCP_F_INIT_FAILED before calling
nvmet_req_uninit(), matching the existing pattern in
nvmet_tcp_execute_request().

Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Shivam Kumar &lt;kumar.shivam43666@gmail.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
[shivam: inlined nvmet_tcp_finish_cmd() at the fix site for 5.15.y]
Signed-off-by: Shivam Kumar &lt;kumar.shivam43666@gmail.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>nvmet-rdma: handle inline data with a nonzero offset</title>
<updated>2026-07-24T13:51:51+00:00</updated>
<author>
<name>Bryam Vargas</name>
<email>hexlabsecurity@proton.me</email>
</author>
<published>2026-06-04T19:36:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=bf8bcc1c137d54a62a428b00051fdbb13660673b'/>
<id>urn:sha1:bf8bcc1c137d54a62a428b00051fdbb13660673b</id>
<content type='text'>
commit 48c0162f647bb47e6084ffbc71b8f213f5e2f4f8 upstream.

nvmet_rdma_use_inline_sg() maps the host-controlled inline data offset
into the per-command inline scatterlist.  The bounds check admits any
offset with off + len &lt;= inline_data_size, but the mapping still assumes
the data begins in the first inline page:

	sg-&gt;offset = off;
	sg-&gt;length = min_t(int, len, PAGE_SIZE - off);

When a port is configured with inline_data_size &gt; PAGE_SIZE (settable up
to max(SZ_16K, PAGE_SIZE)), an offset in (PAGE_SIZE, inline_data_size]
makes "PAGE_SIZE - off" underflow, so sg-&gt;length is set to ~4 GiB and
the block backend reads far past the first inline page.  num_pages(len)
also ignores the offset, so an in-bounds offset whose [off, off+len)
span crosses a page boundary under-counts the scatterlist.

Map the offset properly: split it into a page index and an in-page
offset, start the scatterlist at that page, and size the page count from
page_off + len.  Because the request scatterlist may now start at
inline_sg[page_idx] rather than inline_sg[0], generalize the inline-SGL
identity test in nvmet_rdma_release_rsp() to a range test; otherwise the
persistent inline scatterlist is mistaken for an allocated one and
nvmet_req_free_sgls() frees an inline page (and warns in
free_large_kmalloc()).

Fixes: 0d5ee2b2ab4f ("nvmet-rdma: support max(16KB, PAGE_SIZE) inline data")
Cc: stable@vger.kernel.org
Suggested-by: Keith Busch &lt;kbusch@kernel.org&gt;
Reported-by: Bryam Vargas &lt;hexlabsecurity@proton.me&gt;
Signed-off-by: Bryam Vargas &lt;hexlabsecurity@proton.me&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>nvme-multipath: fix flex array size in struct nvme_ns_head</title>
<updated>2026-07-24T13:51:30+00:00</updated>
<author>
<name>Nilay Shroff</name>
<email>nilay@linux.ibm.com</email>
</author>
<published>2026-05-27T06:20:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=316b5f1168264844aa125959de1d6da2b1905795'/>
<id>urn:sha1:316b5f1168264844aa125959de1d6da2b1905795</id>
<content type='text'>
[ Upstream commit 001e57554de81aa79c25c18fd53911d8a415c304 ]

struct nvme_ns_head contains a flexible array member, current_path[],
which is indexed using the NUMA node ID:
head-&gt;current_path[numa_node_id()]

The structure is currently allocated as:
size = sizeof(struct nvme_ns_head) +
       (num_possible_nodes() * sizeof(struct nvme_ns *));
head = kzalloc(size, GFP_KERNEL);

This allocation assumes that NUMA node IDs are sequential and densely
packed from 0 .. num_possible_nodes() - 1. While this assumption holds
on many systems, it is not always true on some architectures such as
powerpc.

On some powerpc systems, NUMA node IDs can be sparse. For example:
NUMA:
  NUMA node(s):              6
  NUMA node0 CPU(s):         80-159
  NUMA node8 CPU(s):         0-79
  NUMA node252 CPU(s):
  NUMA node253 CPU(s):
  NUMA node254 CPU(s):
  NUMA node255 CPU(s):

That is, the possible/online NUMA node IDs are: 0, 8, 252, 253, 254, 255
In this case: num_possible_nodes() = 6

So memory is allocated for only 6 entries in current_path[]. However,
the array is later indexed using the actual NUMA node ID. As a result,
accesses such as:
head-&gt;current_path[8] or
head-&gt;current_path[252]
goes out of bounds, leading to the following KASAN splat:

==================================================================
BUG: KASAN: slab-out-of-bounds in nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core]
Write of size 8 at addr c00020003bda35b8 by task kworker/u641:2/1997

CPU: 1 UID: 0 PID: 1997 Comm: kworker/u641:2 Not tainted 7.1.0-rc5-dirty #14 PREEMPT(lazy)
Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV
Workqueue: async async_run_entry_fn
Call Trace:
[c000200037fa7510] [c0000000021c23d4] dump_stack_lvl+0x88/0xdc (unreliable)
[c000200037fa7540] [c0000000009fda90] print_report+0x22c/0x67c
[c000200037fa7630] [c0000000009fd508] kasan_report+0x108/0x220
[c000200037fa7740] [c0000000009fff48] __asan_store8+0xe8/0x120
[c000200037fa7760] [c008000018e76474] nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core]
[c000200037fa7800] [c008000018e6556c] nvme_update_ns_info+0x4a4/0x5e0 [nvme_core]
[c000200037fa7a50] [c008000018e66270] nvme_alloc_ns+0x6d8/0x1a70 [nvme_core]
[c000200037fa7c20] [c008000018e679fc] nvme_scan_ns+0x3f4/0x630 [nvme_core]
[c000200037fa7d10] [c00000000031f22c] async_run_entry_fn+0x9c/0x3a0
[c000200037fa7db0] [c0000000002fa544] process_one_work+0x414/0xa10
[c000200037fa7ec0] [c0000000002fbf00] worker_thread+0x320/0x640
[c000200037fa7f80] [c00000000030d0f8] kthread+0x278/0x290
[c000200037fa7fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18

Allocated by task 1997 on cpu 1 at 35.928317s:

The buggy address belongs to the object at c00020003bda3000
 which belongs to the cache kmalloc-rnd-15-2k of size 2048
The buggy address is located 16 bytes to the right of
 allocated 1448-byte region [c00020003bda3000, c00020003bda35a8)

The buggy address belongs to the physical page:

Memory state around the buggy address:
 c00020003bda3480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 c00020003bda3500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
&gt;c00020003bda3580: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                        ^
 c00020003bda3600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 c00020003bda3680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Fix this by allocating the flexible array using nr_node_ids instead
of num_possible_nodes(). Since nr_node_ids represents the maximum
possible NUMA node IDs, indexing current_path[] using numa_node_id()
becomes safe even on systems with sparse node IDs.

Fixes: f333444708f8 ("nvme: take node locality into account when selecting a path")
Tested-by: Mukesh Kumar Chaurasiya (IBM) &lt;mkchauras@gmail.com&gt;
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) &lt;mkchauras@gmail.com&gt;
Reviewed-by: Hannes Reinecke &lt;hare@kernel.org&gt;
Reviewed-by: John Garry &lt;john.g.garry@oracle.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Nilay Shroff &lt;nilay@linux.ibm.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>nvme-multipath: set BIO_REMAPPED on bios remapped to per-path namespace disks</title>
<updated>2026-07-24T13:51:24+00:00</updated>
<author>
<name>Achkinazi, Igor</name>
<email>Igor.Achkinazi@dell.com</email>
</author>
<published>2026-05-28T15:24:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f221e79018e4bd780df58caa0d684750c00bead4'/>
<id>urn:sha1:f221e79018e4bd780df58caa0d684750c00bead4</id>
<content type='text'>
commit 88bac2c1a72b8f4f71e9845699aa872df04e5850 upstream.

When nvme_ns_head_submit_bio() remaps a bio from the multipath head to a
per-path namespace, bio_set_dev() clears BIO_REMAPPED.  The remapped bio
is then resubmitted through submit_bio_noacct() which calls
bio_check_eod() because BIO_REMAPPED is not set.

This races with nvme_ns_remove() which zeroes the per-path capacity
before synchronize_srcu():

  CPU 0 (IO submission)
  ---------------------
  srcu_read_lock()
  nvme_find_path() -&gt; ns
    [NVME_NS_READY is set]

  CPU 1 (namespace removal)
  -------------------------
  clear_bit(NVME_NS_READY)
  set_capacity(ns-&gt;disk, 0)
  synchronize_srcu()  &lt;- blocks

  CPU 0 (IO submission)
  ---------------------
  bio_set_dev(bio, ns-&gt;disk-&gt;part0)
    [clears BIO_REMAPPED]
  submit_bio_noacct(bio)
    -&gt; bio_check_eod() sees capacity=0
    -&gt; bio fails with IO error

The SRCU read lock prevents synchronize_srcu() from completing, but does
not prevent set_capacity(0) from executing.  The bio fails the EOD check
before it reaches the NVMe driver, so nvme_failover_req() never gets a
chance to redirect it to another path of multipath.  IO errors are
reported to the application despite another path being available.

On older kernels (before commit 0b64682e78f7 "block: skip unnecessary
checks for split bio"), the same race was also reachable through split
remainders resubmitted via submit_bio_noacct().

Fix this by setting BIO_REMAPPED after bio_set_dev() in
nvme_ns_head_submit_bio().  This skips bio_check_eod() on the per-path
device; the EOD check already passed on the multipath head.

NVMe per-path namespace devices are always whole disks (bd_partno=0), so
the blk_partition_remap() skip also gated by BIO_REMAPPED is a no-op.
The flag does not persist across failover and cannot go stale if the
namespace geometry changes between attempts: nvme_failover_req() calls
bio_set_dev() to redirect the bio back to the multipath head, which
clears BIO_REMAPPED.  When nvme_requeue_work() resubmits through
submit_bio_noacct(), bio_check_eod() runs normally against the current
capacity.

Same approach as commit 3a905c37c351 ("block: skip bio_check_eod for
partition-remapped bios").

Fixes: a7c7f7b2b641 ("nvme: use bio_set_dev to assign -&gt;bi_bdev")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Igor Achkinazi &lt;igor.achkinazi@dell.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>nvmet-tcp: fix race between ICReq handling and queue teardown</title>
<updated>2026-07-24T13:51:15+00:00</updated>
<author>
<name>Chaitanya Kulkarni</name>
<email>kch@nvidia.com</email>
</author>
<published>2026-07-02T12:37:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9c63cf80895a70eb4fcfcaa725bb1ac9ae76f02b'/>
<id>urn:sha1:9c63cf80895a70eb4fcfcaa725bb1ac9ae76f02b</id>
<content type='text'>
commit 5293a8882c549fab4a878bc76b0b6c951f980a61 upstream.

nvmet_tcp_handle_icreq() updates queue-&gt;state after sending an
Initialization Connection Response (ICResp), but it does so without
serializing against target-side queue teardown.

If an NVMe/TCP host sends an Initialization Connection Request
(ICReq) and immediately closes the connection, target-side teardown
may start in softirq context before io_work drains the already
buffered ICReq. In that case, nvmet_tcp_schedule_release_queue()
sets queue-&gt;state to NVMET_TCP_Q_DISCONNECTING and drops the queue
reference under state_lock.

If io_work later processes that ICReq, nvmet_tcp_handle_icreq() can
still overwrite the state back to NVMET_TCP_Q_LIVE. That defeats the
DISCONNECTING-state guard in nvmet_tcp_schedule_release_queue() and
allows a later socket state change to re-enter teardown and issue a
second kref_put() on an already released queue.

The ICResp send failure path has the same problem. If teardown has
already moved the queue to DISCONNECTING, a send error can still
overwrite the state with NVMET_TCP_Q_FAILED, again reopening the
window for a second teardown path to drop the queue reference.

Fix this by serializing both post-send state transitions with
state_lock and bailing out if teardown has already started.

Use -ESHUTDOWN as an internal sentinel for that bail-out path rather
than propagating it as a transport error like -ECONNRESET. Keep
nvmet_tcp_socket_error() setting rcv_state to NVMET_TCP_RECV_ERR before
honoring that sentinel so receive-side parsing stays quiesced until the
existing release path completes.

Fixes: c46a6465bac2 ("nvmet-tcp: add NVMe over TCP target driver")
Cc: stable@vger.kernel.org
Reported-by: Shivam Kumar &lt;skumar47@syr.edu&gt;
Tested-by: Shivam Kumar &lt;kumar.shivam43666@gmail.com&gt;
Signed-off-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
[ context diff adaptation: drop `queue-&gt;state = NVMET_TCP_Q_FAILED` since
 the enum introduced in 6.7, 675b453e0241 ("nvmet-tcp: enable TLS handshake
 upcall" ]
Signed-off-by: Philo Lu &lt;lulie@linux.alibaba.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>use less confusing names for iov_iter direction initializers</title>
<updated>2026-06-19T11:33:46+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2026-05-30T11:40:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=31882893cafa120d76059cc080eac3bec24495df'/>
<id>urn:sha1:31882893cafa120d76059cc080eac3bec24495df</id>
<content type='text'>
[ Upstream commit de4eda9de2d957ef2d6a8365a01e26a435e958cb ]

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Stable-dep-of: a4f0b001782b ("vsock/virtio: reset connection on receiving queue overflow")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free</title>
<updated>2026-06-01T15:35:23+00:00</updated>
<author>
<name>Chaitanya Kulkarni</name>
<email>kch@nvidia.com</email>
</author>
<published>2026-04-09T00:56:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8d66ba89480ff098a58d79003a505f383aa4e920'/>
<id>urn:sha1:8d66ba89480ff098a58d79003a505f383aa4e920</id>
<content type='text'>
commit aade8abd8b868b6ffa9697aadaea28ec7f65bee6 upstream.

nvmet_tcp_release_queue_work() runs on nvmet-wq and can drop the
final controller reference through nvmet_cq_put(). If that triggers
nvmet_ctrl_free(), the teardown path flushes ctrl-&gt;async_event_work on
the same nvmet-wq.

Call chain:

 nvmet_tcp_schedule_release_queue()
   kref_put(&amp;queue-&gt;kref, nvmet_tcp_release_queue)
     nvmet_tcp_release_queue()
       queue_work(nvmet_wq, &amp;queue-&gt;release_work) &lt;--- nvmet_wq
         process_one_work()
           nvmet_tcp_release_queue_work()
             nvmet_cq_put(&amp;queue-&gt;nvme_cq)
               nvmet_cq_destroy()
                 nvmet_ctrl_put(cq-&gt;ctrl)
                   nvmet_ctrl_free()
                     flush_work(&amp;ctrl-&gt;async_event_work) &lt;--- nvmet_wq

                      Previously Scheduled by :-
		        nvmet_add_async_event
		          queue_work(nvmet_wq, &amp;ctrl-&gt;async_event_work);

This trips lockdep with a possible recursive locking warning.

[ 5223.015876] run blktests nvme/003 at 2026-04-07 20:53:55
[ 5223.061801] loop0: detected capacity change from 0 to 2097152
[ 5223.072206] nvmet: adding nsid 1 to subsystem blktests-subsystem-1
[ 5223.088368] nvmet_tcp: enabling port 0 (127.0.0.1:4420)
[ 5223.126086] nvmet: Created discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
[ 5223.128453] nvme nvme1: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349
[ 5233.199447] nvme nvme1: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"

[ 5233.227718] ============================================
[ 5233.231283] WARNING: possible recursive locking detected
[ 5233.234696] 7.0.0-rc3nvme+ #20 Tainted: G           O     N
[ 5233.238434] --------------------------------------------
[ 5233.241852] kworker/u192:6/2413 is trying to acquire lock:
[ 5233.245429] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90
[ 5233.251438]
               but task is already holding lock:
[ 5233.255254] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0
[ 5233.261125]
               other info that might help us debug this:
[ 5233.265333]  Possible unsafe locking scenario:

[ 5233.269217]        CPU0
[ 5233.270795]        ----
[ 5233.272436]   lock((wq_completion)nvmet-wq);
[ 5233.275241]   lock((wq_completion)nvmet-wq);
[ 5233.278020]
                *** DEADLOCK ***

[ 5233.281793]  May be due to missing lock nesting notation

[ 5233.286195] 3 locks held by kworker/u192:6/2413:
[ 5233.289192]  #0: ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0
[ 5233.294569]  #1: ffffc9000e2a7e40 ((work_completion)(&amp;queue-&gt;release_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x6e0
[ 5233.300128]  #2: ffffffff82d7dc40 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530
[ 5233.304290]
               stack backtrace:
[ 5233.306520] CPU: 4 UID: 0 PID: 2413 Comm: kworker/u192:6 Tainted: G           O     N  7.0.0-rc3nvme+ #20 PREEMPT(full)
[ 5233.306524] Tainted: [O]=OOT_MODULE, [N]=TEST
[ 5233.306525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 5233.306527] Workqueue: nvmet-wq nvmet_tcp_release_queue_work [nvmet_tcp]
[ 5233.306532] Call Trace:
[ 5233.306534]  &lt;TASK&gt;
[ 5233.306536]  dump_stack_lvl+0x73/0xb0
[ 5233.306552]  print_deadlock_bug+0x225/0x2f0
[ 5233.306556]  __lock_acquire+0x13f0/0x2290
[ 5233.306563]  lock_acquire+0xd0/0x300
[ 5233.306565]  ? touch_wq_lockdep_map+0x26/0x90
[ 5233.306571]  ? __flush_work+0x20b/0x530
[ 5233.306573]  ? touch_wq_lockdep_map+0x26/0x90
[ 5233.306577]  touch_wq_lockdep_map+0x3b/0x90
[ 5233.306580]  ? touch_wq_lockdep_map+0x26/0x90
[ 5233.306583]  ? __flush_work+0x20b/0x530
[ 5233.306585]  __flush_work+0x268/0x530
[ 5233.306588]  ? __pfx_wq_barrier_func+0x10/0x10
[ 5233.306594]  ? xen_error_entry+0x30/0x60
[ 5233.306600]  nvmet_ctrl_free+0x140/0x310 [nvmet]
[ 5233.306617]  nvmet_cq_put+0x74/0x90 [nvmet]
[ 5233.306629]  nvmet_tcp_release_queue_work+0x19f/0x360 [nvmet_tcp]
[ 5233.306634]  process_one_work+0x206/0x6e0
[ 5233.306640]  worker_thread+0x184/0x320
[ 5233.306643]  ? __pfx_worker_thread+0x10/0x10
[ 5233.306646]  kthread+0xf1/0x130
[ 5233.306648]  ? __pfx_kthread+0x10/0x10
[ 5233.306651]  ret_from_fork+0x355/0x450
[ 5233.306653]  ? __pfx_kthread+0x10/0x10
[ 5233.306656]  ret_from_fork_asm+0x1a/0x30
[ 5233.306664]  &lt;/TASK&gt;

There is also no need to flush async_event_work from controller
teardown. The admin queue teardown already fails outstanding AER
requests before the final controller put :-

 nvmet_sq_destroy(admin sq)
    nvmet_async_events_failall(ctrl)

The controller has already been removed from the subsystem list before
nvmet_ctrl_free() quiesces outstanding work.

Replace flush_work() with cancel_work_sync() so a pending
async_event_work item is canceled and a running instance is waited on
without recursing into the same workqueue.

Fixes: 06406d81a2d7 ("nvmet: cancel fatal error and flush async work before free controller")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
