[PATCH v2] wifi: brcmfmac: Fix potential kernel oops when probe fails

When probe of the sdio brcmfmac device fails for some reasons (i.e.
missing firmware), the sdiodev->bus is set to error instead of NULL, thus
the cleanup later in brcmf_sdio_remove() tries to free resources via
invalid bus pointer. This happens because sdiodev->bus is set 2 times:
first in brcmf_sdio_probe() and second time in brcmf_sdiod_probe(). Fix
this by chaning the brcmf_sdio_probe() function to return the error code
and set sdio->bus only there.

Fixes: 0ff0843310b7 ("wifi: brcmfmac: Add optional lpo clock enable support")
Signed-off-by: Marek Szyprowski <[email protected]>
---
Changelog:
v2:
- changed return type of brcmf_sdio_probe() function

v1: https://lore.kernel.org/all/[email protected]
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 7 +++----
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c   | 7 ++++---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h   | 2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
index 6a3f187320fc..13952dfeb3e3 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
@@ -951,11 +951,10 @@ int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev)
 		goto out;
 
 	/* try to attach to the target device */
-	sdiodev->bus = brcmf_sdio_probe(sdiodev);
-	if (IS_ERR(sdiodev->bus)) {
-		ret = PTR_ERR(sdiodev->bus);
+	ret = brcmf_sdio_probe(sdiodev);
+	if (ret)
 		goto out;
-	}
+
 	brcmf_sdiod_host_fixup(sdiodev->func2->card->host);
 out:
 	if (ret)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 8cf9d7e7c3f7..4e6ed02c1591 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -4445,7 +4445,7 @@ brcmf_sdio_prepare_fw_request(struct brcmf_sdio *bus)
 	return fwreq;
 }
 
-struct brcmf_sdio *brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev)
+int brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev)
 {
 	int ret;
 	struct brcmf_sdio *bus;
@@ -4551,11 +4551,12 @@ struct brcmf_sdio *brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev)
 		goto fail;
 	}
 
-	return bus;
+	return 0;
 
 fail:
 	brcmf_sdio_remove(bus);
-	return ERR_PTR(ret);
+	sdiodev->bus = NULL;
+	return ret;
 }
 
 /* Detach and free everything */
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h
index 0d18ed15b403..80180d5c6c87 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h
@@ -358,7 +358,7 @@ void brcmf_sdiod_freezer_uncount(struct brcmf_sdio_dev *sdiodev);
 int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev);
 int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev);
 
-struct brcmf_sdio *brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev);
+int brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev);
 void brcmf_sdio_remove(struct brcmf_sdio *bus);
 void brcmf_sdio_isr(struct brcmf_sdio *bus, bool in_isr);
 
-- 
2.34.1