diff options
| author | Andrew Jeffery <andrew@codeconstruct.com.au> | 2025-06-16 22:43:39 +0930 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-24 08:56:27 +0200 |
| commit | b361598b7352f02456619a6105c7da952ef69f8f (patch) | |
| tree | cecee1b51641f69a57e019a427d0abc627a1ac7e | |
| parent | 855d4da5f270a3c29e01613d199d8bfd635af81d (diff) | |
soc: aspeed: lpc-snoop: Don't disable channels that aren't enabled
commit 56448e78a6bb4e1a8528a0e2efe94eff0400c247 upstream.
Mitigate e.g. the following:
# echo 1e789080.lpc-snoop > /sys/bus/platform/drivers/aspeed-lpc-snoop/unbind
...
[ 120.363594] Unable to handle kernel NULL pointer dereference at virtual address 00000004 when write
[ 120.373866] [00000004] *pgd=00000000
[ 120.377910] Internal error: Oops: 805 [#1] SMP ARM
[ 120.383306] CPU: 1 UID: 0 PID: 315 Comm: sh Not tainted 6.15.0-rc1-00009-g926217bc7d7d-dirty #20 NONE
...
[ 120.679543] Call trace:
[ 120.679559] misc_deregister from aspeed_lpc_snoop_remove+0x84/0xac
[ 120.692462] aspeed_lpc_snoop_remove from platform_remove+0x28/0x38
[ 120.700996] platform_remove from device_release_driver_internal+0x188/0x200
...
Fixes: 9f4f9ae81d0a ("drivers/misc: add Aspeed LPC snoop driver")
Cc: stable@vger.kernel.org
Cc: Jean Delvare <jdelvare@suse.de>
Acked-by: Jean Delvare <jdelvare@suse.de>
Link: https://patch.msgid.link/20250616-aspeed-lpc-snoop-fixes-v2-2-3cdd59c934d3@codeconstruct.com.au
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/soc/aspeed/aspeed-lpc-snoop.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c index 4c2f83b75f1c..54db2abc2e2a 100644 --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c @@ -58,6 +58,7 @@ struct aspeed_lpc_snoop_model_data { }; struct aspeed_lpc_snoop_channel { + bool enabled; struct kfifo fifo; wait_queue_head_t wq; struct miscdevice miscdev; @@ -190,6 +191,9 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop, const struct aspeed_lpc_snoop_model_data *model_data = of_device_get_match_data(dev); + if (WARN_ON(lpc_snoop->chan[channel].enabled)) + return -EBUSY; + init_waitqueue_head(&lpc_snoop->chan[channel].wq); /* Create FIFO datastructure */ rc = kfifo_alloc(&lpc_snoop->chan[channel].fifo, @@ -236,6 +240,8 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop, regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en); + lpc_snoop->chan[channel].enabled = true; + return 0; err_misc_deregister: @@ -248,6 +254,9 @@ err_free_fifo: static void aspeed_lpc_disable_snoop(struct aspeed_lpc_snoop *lpc_snoop, int channel) { + if (!lpc_snoop->chan[channel].enabled) + return; + switch (channel) { case 0: regmap_update_bits(lpc_snoop->regmap, HICR5, @@ -263,6 +272,8 @@ static void aspeed_lpc_disable_snoop(struct aspeed_lpc_snoop *lpc_snoop, return; } + lpc_snoop->chan[channel].enabled = false; + /* Consider improving safety wrt concurrent reader(s) */ misc_deregister(&lpc_snoop->chan[channel].miscdev); kfifo_free(&lpc_snoop->chan[channel].fifo); } |