[PATCH AUTOSEL 5.15 24/46] drm/mediatek: Fix return type of mtk_hdmi_bridge_mode_valid()

[PATCH AUTOSEL 5.15 24/46] drm/mediatek: Fix return type of mtk_hdmi_bridge_mode_valid()

[Sasha Levin]

From: Nathan Chancellor <nathan@kernel.org>

[ Upstream commit 890d637523eec9d730e3885532fa1228ba678880 ]

With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
proposed warning in clang aims to catch these at compile time, which
reveals:

  drivers/gpu/drm/mediatek/mtk_hdmi.c:1407:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
          .mode_valid = mtk_hdmi_bridge_mode_valid,
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~
  1 error generated.

->mode_valid() in 'struct drm_bridge_funcs' expects a return type of
'enum drm_mode_status', not 'int'. Adjust the return type of
mtk_hdmi_bridge_mode_valid() to match the prototype's to resolve the
warning and CFI failure.

Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_hdmi.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 3196189429bc..7613b0fa2be6 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -1203,9 +1203,10 @@ static enum drm_connector_status mtk_hdmi_detect(struct mtk_hdmi *hdmi)
 	return mtk_hdmi_update_plugged_status(hdmi);
 }
 
-static int mtk_hdmi_bridge_mode_valid(struct drm_bridge *bridge,
-				      const struct drm_display_info *info,
-				      const struct drm_display_mode *mode)
+static enum drm_mode_status
+mtk_hdmi_bridge_mode_valid(struct drm_bridge *bridge,
+			   const struct drm_display_info *info,
+			   const struct drm_display_mode *mode)
 {
 	struct mtk_hdmi *hdmi = hdmi_ctx_from_bridge(bridge);
 	struct drm_bridge *next_bridge;
-- 
2.35.1

[PATCH AUTOSEL 5.15 42/46] wifi: mt76: do not run mt76u_status_worker if the device is not running

[Sasha Levin]

From: Lorenzo Bianconi <lorenzo@kernel.org>

[ Upstream commit bd5dac7ced5a7c9faa4dc468ac9560c3256df845 ]

Fix the following NULL pointer dereference avoiding to run
mt76u_status_worker thread if the device is not running yet.

KASAN: null-ptr-deref in range
[0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 98 Comm: kworker/u2:2 Not tainted 5.14.0+ #78 Hardware
name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: mt76 mt76u_tx_status_data
RIP: 0010:mt76x02_mac_fill_tx_status.isra.0+0x82c/0x9e0
Code: c5 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 94 01 00 00
48 b8 00 00 00 00 00 fc ff df 4d 8b 34 24 4c 89 f2 48 c1 ea 03 <0f>
b6
04 02 84 c0 74 08 3c 03 0f 8e 89 01 00 00 41 8b 16 41 0f b7
RSP: 0018:ffffc900005af988 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffc900005afae8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff832fc661 RDI: ffffc900005afc2a
RBP: ffffc900005afae0 R08: 0000000000000001 R09: fffff520000b5f3c
R10: 0000000000000003 R11: fffff520000b5f3b R12: ffff88810b6132d8
R13: 000000000000ffff R14: 0000000000000000 R15: ffffc900005afc28
FS:  0000000000000000(0000) GS:ffff88811aa00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa0eda6a000 CR3: 0000000118f17000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
 mt76x02_send_tx_status+0x1d2/0xeb0
 mt76x02_tx_status_data+0x8e/0xd0
 mt76u_tx_status_data+0xe1/0x240
 process_one_work+0x92b/0x1460
 worker_thread+0x95/0xe00
 kthread+0x3a1/0x480
 ret_from_fork+0x1f/0x30
Modules linked in:
--[ end trace 8df5d20fc5040f65 ]--
RIP: 0010:mt76x02_mac_fill_tx_status.isra.0+0x82c/0x9e0
Code: c5 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 94 01 00 00
48 b8 00 00 00 00 00 fc ff df 4d 8b 34 24 4c 89 f2 48 c1 ea 03 <0f>
b6
04 02 84 c0 74 08 3c 03 0f 8e 89 01 00 00 41 8b 16 41 0f b7
RSP: 0018:ffffc900005af988 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffc900005afae8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff832fc661 RDI: ffffc900005afc2a
RBP: ffffc900005afae0 R08: 0000000000000001 R09: fffff520000b5f3c
R10: 0000000000000003 R11: fffff520000b5f3b R12: ffff88810b6132d8
R13: 000000000000ffff R14: 0000000000000000 R15: ffffc900005afc28
FS:  0000000000000000(0000) GS:ffff88811aa00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa0eda6a000 CR3: 0000000118f17000 CR4: 0000000000750ef0
PKRU: 55555554

Moreover move stat_work schedule out of the for loop.

Reported-by: Dokyung Song <dokyungs@yonsei.ac.kr>
Co-developed-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/mediatek/mt76/usb.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
index 1e9f60bb811a..b47343e321b8 100644
--- a/drivers/net/wireless/mediatek/mt76/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/usb.c
@@ -814,6 +814,9 @@ static void mt76u_status_worker(struct mt76_worker *w)
 	struct mt76_queue *q;
 	int i;
 
+	if (!test_bit(MT76_STATE_RUNNING, &dev->phy.state))
+		return;
+
 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
 		q = dev->phy.q_tx[i];
 		if (!q)
@@ -833,11 +836,11 @@ static void mt76u_status_worker(struct mt76_worker *w)
 			wake_up(&dev->tx_wait);
 
 		mt76_worker_schedule(&dev->tx_worker);
-
-		if (dev->drv->tx_status_data &&
-		    !test_and_set_bit(MT76_READING_STATS, &dev->phy.state))
-			queue_work(dev->wq, &dev->usb.stat_work);
 	}
+
+	if (dev->drv->tx_status_data &&
+	    !test_and_set_bit(MT76_READING_STATS, &dev->phy.state))
+		queue_work(dev->wq, &dev->usb.stat_work);
 }
 
 static void mt76u_tx_status_data(struct work_struct *work)
-- 
2.35.1