[PATCH wireless] wifi: brcmfmac: initialize SDIO data work before cleanup

[Runyu Xiao]

brcmf_sdio_probe() stores the newly allocated bus in sdiodev->bus before
allocating the ordered workqueue. If that allocation fails, the function
jumps to fail and calls brcmf_sdio_remove().

brcmf_sdio_remove() unconditionally cancels bus->datawork. Initialize the
work item before the first failure path that can reach brcmf_sdio_remove(),
so the cleanup path always observes a valid work object.

This issue was found by our static analysis tool and then confirmed by
manual review of the probe error path and the remove-time work drain. The
problem pattern is an early setup failure that reaches a cleanup helper
which cancels an embedded work item before its initializer has run.

A QEMU PoC forced alloc_ordered_workqueue() to fail at the same point in
brcmf_sdio_probe(), before INIT_WORK(&bus->datawork) is reached. The
resulting fail path calls brcmf_sdio_remove(), and DEBUG_OBJECTS reports
the invalid work drain with brcmf_sdio_probe() and brcmf_sdio_remove() in
the stack.

Fixes: 9982464379e8 ("brcmfmac: make sdio suspend wait for threads to freeze")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Runyu Xiao <runyu.xiao@xxxxxxxxxx>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 4e6ed02c1591..a7d84ad6ed54 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -4464,6 +4464,7 @@ int brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev)
 	bus->sdiodev = sdiodev;
 	sdiodev->bus = bus;
 	skb_queue_head_init(&bus->glom);
+	INIT_WORK(&bus->datawork, brcmf_sdio_dataworker);
 	bus->txbound = BRCMF_TXBOUND;
 	bus->rxbound = BRCMF_RXBOUND;
 	bus->txminmax = BRCMF_TXMINMAX;
@@ -4478,7 +4479,6 @@ int brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev)
 		goto fail;
 	}
 	brcmf_sdiod_freezer_count(sdiodev);
-	INIT_WORK(&bus->datawork, brcmf_sdio_dataworker);
 	bus->brcmf_wq = wq;
 
 	/* attempt to attach to the dongle */
-- 
2.34.1