[PATCH 6.18 443/752] net: mana: Fix double destroy_workqueue on service rescan PCI path

Sasha Levin
2026-02-28T17:54:19Z

From: Dipayaan Roy <dipayanroy@linux.microsoft.com>

[ Upstream commit f975a0955276579e2176a134366ed586071c7c6a ]

While testing corner cases in the driver, a use-after-free crash
was found on the service rescan PCI path.

When mana_serv_reset() calls mana_gd_suspend(), mana_gd_cleanup()
destroys gc->service_wq. If the subsequent mana_gd_resume() fails
with -ETIMEDOUT or -EPROTO, the code falls through to
mana_serv_rescan() which triggers pci_stop_and_remove_bus_device().
This invokes the PCI .remove callback (mana_gd_remove), which calls
mana_gd_cleanup() a second time, attempting to destroy the already-
freed workqueue. Fix this by NULL-checking gc->service_wq in
mana_gd_cleanup() and setting it to NULL after destruction.

Call stack of issue for reference:
[Sat Feb 21 18:53:48 2026] Call Trace:
[Sat Feb 21 18:53:48 2026] <TASK>
[Sat Feb 21 18:53:48 2026] mana_gd_cleanup+0x33/0x70 [mana]
[Sat Feb 21 18:53:48 2026] mana_gd_remove+0x3a/0xc0 [mana]
[Sat Feb 21 18:53:48 2026] pci_device_remove+0x41/0xb0
[Sat Feb 21 18:53:48 2026] device_remove+0x46/0x70
[Sat Feb 21 18:53:48 2026] device_release_driver_internal+0x1e3/0x250
[Sat Feb 21 18:53:48 2026] device_release_driver+0x12/0x20
[Sat Feb 21 18:53:48 2026] pci_stop_bus_device+0x6a/0x90
[Sat Feb 21 18:53:48 2026] pci_stop_and_remove_bus_device+0x13/0x30
[Sat Feb 21 18:53:48 2026] mana_do_service+0x180/0x290 [mana]
[Sat Feb 21 18:53:48 2026] mana_serv_func+0x24/0x50 [mana]
[Sat Feb 21 18:53:48 2026] process_one_work+0x190/0x3d0
[Sat Feb 21 18:53:48 2026] worker_thread+0x16e/0x2e0
[Sat Feb 21 18:53:48 2026] kthread+0xf7/0x130
[Sat Feb 21 18:53:48 2026] ? __pfx_worker_thread+0x10/0x10
[Sat Feb 21 18:53:48 2026] ? __pfx_kthread+0x10/0x10
[Sat Feb 21 18:53:48 2026] ret_from_fork+0x269/0x350
[Sat Feb 21 18:53:48 2026] ? __pfx_kthread+0x10/0x10
[Sat Feb 21 18:53:48 2026] ret_from_fork_asm+0x1a/0x30
[Sat Feb 21 18:53:48 2026] </TASK>

Fixes: 505cc26bcae0 ("net: mana: Add support for auxiliary device servicing events")
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Dipayaan Roy <dipayanroy@linux.microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/aZ2bzL64NagfyHpg@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/microsoft/mana/gdma_main.c | 5 ++++-
drivers/net/ethernet/microsoft/mana/mana_en.c | 4 +++-
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 43f034e180c41..e22a98a9c9856 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -1866,7 +1866,10 @@ static void mana_gd_cleanup(struct pci_dev *pdev)

mana_gd_remove_irqs(pdev);

- destroy_workqueue(gc->service_wq);
+ if (gc->service_wq) {
+ destroy_workqueue(gc->service_wq);
+ gc->service_wq = NULL;
+ }
dev_dbg(&pdev->dev, "mana gdma cleanup successful\n");
}

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 0142fd98392c2..5712ec4f644a4 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -3580,7 +3580,9 @@ void mana_rdma_remove(struct gdma_dev *gd)
}

WRITE_ONCE(gd->rdma_teardown, true);
- flush_workqueue(gc->service_wq);
+
+ if (gc->service_wq)
+ flush_workqueue(gc->service_wq);

if (gd->adev)
remove_adev(gd);
--
2.51.0