This is a note to let you know that I've just added the patch titled
PCI/DOE: Fix destroy_work_on_stack() race
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-doe-fix-destroy_work_on_stack-race.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1d9729e89e2fa95c11106ff4de699be0a71893e9
Author: Ira Weiny <ira.weiny@xxxxxxxxx>
Date: Wed Jul 26 11:29:42 2023 -0700
PCI/DOE: Fix destroy_work_on_stack() race
[ Upstream commit e3a3a097eaebaf234a482b4d2f9f18fe989208c1 ]
The following debug object splat was observed in testing:
ODEBUG: free active (active state 0) object: 0000000097d23782 object type: work_struct hint: doe_statemachine_work+0x0/0x510
WARNING: CPU: 1 PID: 71 at lib/debugobjects.c:514 debug_print_object+0x7d/0xb0
...
Workqueue: pci 0000:36:00.0 DOE [1 doe_statemachine_work
RIP: 0010:debug_print_object+0x7d/0xb0
...
Call Trace:
? debug_print_object+0x7d/0xb0
? __pfx_doe_statemachine_work+0x10/0x10
debug_object_free.part.0+0x11b/0x150
doe_statemachine_work+0x45e/0x510
process_one_work+0x1d4/0x3c0
This occurs because destroy_work_on_stack() was called after signaling
the completion in the calling thread. This creates a race between
destroy_work_on_stack() and the task->work struct going out of scope in
pci_doe().
Signal the work complete after destroying the work struct. This is safe
because signal_task_complete() is the final thing the work item does and
the workqueue code is careful not to access the work struct after.
Fixes: abf04be0e707 ("PCI/DOE: Fix memory leak with CONFIG_DEBUG_OBJECTS=y")
Link: https://lore.kernel.org/r/20230726-doe-fix-v1-1-af07e614d4dd@xxxxxxxxx
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Lukas Wunner <lukas@xxxxxxxxx>
Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
index 1b97a5ab71a96..e3aab5edaf706 100644
--- a/drivers/pci/doe.c
+++ b/drivers/pci/doe.c
@@ -293,8 +293,8 @@ static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *tas
static void signal_task_complete(struct pci_doe_task *task, int rv)
{
task->rv = rv;
- task->complete(task);
destroy_work_on_stack(&task->work);
+ task->complete(task);
}
static void signal_task_abort(struct pci_doe_task *task, int rv)
