[PATCH wireless] wifi: wilc1000: unregister wiphy only if it has been registered

[PATCH wireless] wifi: wilc1000: unregister wiphy only if it has been registered

[Alexis Lothoré]

There is a specific error path in probe functions in wilc drivers (both
sdio and spi) which can lead to kernel panic, as this one for example
when using SPI:

Unable to handle kernel paging request at virtual address 9f000000 when read
[9f000000] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in: wilc1000_spi(+) crc_itu_t crc7 wilc1000 cfg80211 bluetooth ecdh_generic ecc
CPU: 0 UID: 0 PID: 106 Comm: modprobe Not tainted 6.13.0-rc3+ #22
Hardware name: Atmel SAMA5
PC is at wiphy_unregister+0x244/0xc40 [cfg80211]
LR is at wiphy_unregister+0x1c0/0xc40 [cfg80211]
[...]
 wiphy_unregister [cfg80211] from wilc_netdev_cleanup+0x380/0x494 [wilc1000]
 wilc_netdev_cleanup [wilc1000] from wilc_bus_probe+0x360/0x834 [wilc1000_spi]
 wilc_bus_probe [wilc1000_spi] from spi_probe+0x15c/0x1d4
 spi_probe from really_probe+0x270/0xb2c
 really_probe from __driver_probe_device+0x1dc/0x4e8
 __driver_probe_device from driver_probe_device+0x5c/0x140
 driver_probe_device from __driver_attach+0x220/0x540
 __driver_attach from bus_for_each_dev+0x13c/0x1a8
 bus_for_each_dev from bus_add_driver+0x2a0/0x6a4
 bus_add_driver from driver_register+0x27c/0x51c
 driver_register from do_one_initcall+0xf8/0x564
 do_one_initcall from do_init_module+0x2e4/0x82c
 do_init_module from load_module+0x59a0/0x70c4
 load_module from init_module_from_file+0x100/0x148
 init_module_from_file from sys_finit_module+0x2fc/0x924
 sys_finit_module from ret_fast_syscall+0x0/0x1c

The issue can easily be reproduced, for example by not wiring correctly
a wilc device through SPI (and so, make it unresponsive to early SPI
commands). It is due to a recent change decoupling wiphy allocation from
wiphy registration, however wilc_netdev_cleanup has not been updated
accordingly, letting it possibly call wiphy unregister on a wiphy which
has never been registered.

Fix this crash by moving wiphy_unregister/wiphy_free out of
wilc_netdev_cleanup, and by adjusting error paths in both drivers

Fixes: fbdf0c5248dc ("wifi: wilc1000: Register wiphy after reading out chipid")
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
---
 drivers/net/wireless/microchip/wilc1000/netdev.c | 2 --
 drivers/net/wireless/microchip/wilc1000/sdio.c   | 9 +++++++--
 drivers/net/wireless/microchip/wilc1000/spi.c    | 9 +++++++--
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/microchip/wilc1000/netdev.c b/drivers/net/wireless/microchip/wilc1000/netdev.c
index 7e84fc0fd91188b411863b9de647b6d182c6c187..af298021e05041ba4b16a94c8ee768407a208dfc 100644
--- a/drivers/net/wireless/microchip/wilc1000/netdev.c
+++ b/drivers/net/wireless/microchip/wilc1000/netdev.c
@@ -925,8 +925,6 @@ void wilc_netdev_cleanup(struct wilc *wilc)
 
 	wilc_wlan_cfg_deinit(wilc);
 	wlan_deinit_locks(wilc);
-	wiphy_unregister(wilc->wiphy);
-	wiphy_free(wilc->wiphy);
 }
 EXPORT_SYMBOL_GPL(wilc_netdev_cleanup);
 
diff --git a/drivers/net/wireless/microchip/wilc1000/sdio.c b/drivers/net/wireless/microchip/wilc1000/sdio.c
index 5262c8846c13df28cf65ec8c5ad0ef9d6677c98b..3751e2ee1ca95918b589ba9be032984705fa822a 100644
--- a/drivers/net/wireless/microchip/wilc1000/sdio.c
+++ b/drivers/net/wireless/microchip/wilc1000/sdio.c
@@ -193,7 +193,7 @@ static int wilc_sdio_probe(struct sdio_func *func,
 	ret = wilc_load_mac_from_nv(wilc);
 	if (ret) {
 		pr_err("Can not retrieve MAC address from chip\n");
-		goto dispose_irq;
+		goto unregister_wiphy;
 	}
 
 	wilc_sdio_deinit(wilc);
@@ -202,15 +202,18 @@ static int wilc_sdio_probe(struct sdio_func *func,
 				   NL80211_IFTYPE_STATION, false);
 	if (IS_ERR(vif)) {
 		ret = PTR_ERR(vif);
-		goto dispose_irq;
+		goto unregister_wiphy;
 	}
 
 	dev_info(&func->dev, "Driver Initializing success\n");
 	return 0;
 
+unregister_wiphy:
+	wiphy_unregister(wilc->wiphy);
 dispose_irq:
 	irq_dispose_mapping(wilc->dev_irq_num);
 	wilc_netdev_cleanup(wilc);
+	wiphy_free(wilc->wiphy);
 free:
 	kfree(sdio_priv->cmd53_buf);
 	kfree(sdio_priv);
@@ -222,7 +225,9 @@ static void wilc_sdio_remove(struct sdio_func *func)
 	struct wilc *wilc = sdio_get_drvdata(func);
 	struct wilc_sdio *sdio_priv = wilc->bus_data;
 
+	wiphy_unregister(wilc->wiphy);
 	wilc_netdev_cleanup(wilc);
+	wiphy_free(wilc->wiphy);
 	kfree(sdio_priv->cmd53_buf);
 	kfree(sdio_priv);
 }
diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c
index ce2a9cdd6aa7877ed4c2517f9549a00bdc8dc874..31219fd0cfb3fc6df071b3e9be5af17087ccf583 100644
--- a/drivers/net/wireless/microchip/wilc1000/spi.c
+++ b/drivers/net/wireless/microchip/wilc1000/spi.c
@@ -256,7 +256,7 @@ static int wilc_bus_probe(struct spi_device *spi)
 	ret = wilc_load_mac_from_nv(wilc);
 	if (ret) {
 		pr_err("Can not retrieve MAC address from chip\n");
-		goto power_down;
+		goto unregister_wiphy;
 	}
 
 	wilc_wlan_power(wilc, false);
@@ -264,14 +264,17 @@ static int wilc_bus_probe(struct spi_device *spi)
 				   NL80211_IFTYPE_STATION, false);
 	if (IS_ERR(vif)) {
 		ret = PTR_ERR(vif);
-		goto power_down;
+		goto unregister_wiphy;
 	}
 	return 0;
 
+unregister_wiphy:
+	wiphy_unregister(wilc->wiphy);
 power_down:
 	wilc_wlan_power(wilc, false);
 netdev_cleanup:
 	wilc_netdev_cleanup(wilc);
+	wiphy_free(wilc->wiphy);
 free:
 	kfree(spi_priv);
 	return ret;
@@ -282,7 +285,9 @@ static void wilc_bus_remove(struct spi_device *spi)
 	struct wilc *wilc = spi_get_drvdata(spi);
 	struct wilc_spi *spi_priv = wilc->bus_data;
 
+	wiphy_unregister(wilc->wiphy);
 	wilc_netdev_cleanup(wilc);
+	wiphy_free(wilc->wiphy);
 	kfree(spi_priv);
 }
 

---
base-commit: 96997ddfc7c249dbcb6e248986dc2d56ba29ec8b
change-id: 20241223-wilc_fix_probe_error_path-a64be3a9b39a

Best regards,
-- 
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH wireless] wifi: wilc1000: unregister wiphy only if it has been registered

[Marek Vasut]

On 12/23/24 4:46 PM, Alexis Lothoré wrote:
> There is a specific error path in probe functions in wilc drivers (both
> sdio and spi) which can lead to kernel panic, as this one for example
> when using SPI:
> 
> Unable to handle kernel paging request at virtual address 9f000000 when read
> [9f000000] *pgd=00000000
> Internal error: Oops: 5 [#1] ARM
> Modules linked in: wilc1000_spi(+) crc_itu_t crc7 wilc1000 cfg80211 bluetooth ecdh_generic ecc
> CPU: 0 UID: 0 PID: 106 Comm: modprobe Not tainted 6.13.0-rc3+ #22
> Hardware name: Atmel SAMA5
> PC is at wiphy_unregister+0x244/0xc40 [cfg80211]
> LR is at wiphy_unregister+0x1c0/0xc40 [cfg80211]
> [...]
>   wiphy_unregister [cfg80211] from wilc_netdev_cleanup+0x380/0x494 [wilc1000]
>   wilc_netdev_cleanup [wilc1000] from wilc_bus_probe+0x360/0x834 [wilc1000_spi]
>   wilc_bus_probe [wilc1000_spi] from spi_probe+0x15c/0x1d4
>   spi_probe from really_probe+0x270/0xb2c
>   really_probe from __driver_probe_device+0x1dc/0x4e8
>   __driver_probe_device from driver_probe_device+0x5c/0x140
>   driver_probe_device from __driver_attach+0x220/0x540
>   __driver_attach from bus_for_each_dev+0x13c/0x1a8
>   bus_for_each_dev from bus_add_driver+0x2a0/0x6a4
>   bus_add_driver from driver_register+0x27c/0x51c
>   driver_register from do_one_initcall+0xf8/0x564
>   do_one_initcall from do_init_module+0x2e4/0x82c
>   do_init_module from load_module+0x59a0/0x70c4
>   load_module from init_module_from_file+0x100/0x148
>   init_module_from_file from sys_finit_module+0x2fc/0x924
>   sys_finit_module from ret_fast_syscall+0x0/0x1c
> 
> The issue can easily be reproduced, for example by not wiring correctly
> a wilc device through SPI (and so, make it unresponsive to early SPI
> commands). It is due to a recent change decoupling wiphy allocation from
> wiphy registration, however wilc_netdev_cleanup has not been updated
> accordingly, letting it possibly call wiphy unregister on a wiphy which
> has never been registered.
> 
> Fix this crash by moving wiphy_unregister/wiphy_free out of
> wilc_netdev_cleanup, and by adjusting error paths in both drivers
> 
> Fixes: fbdf0c5248dc ("wifi: wilc1000: Register wiphy after reading out chipid")
> Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Nice find, thank you for fixing it.

Reviewed-by: Marek Vasut <marex@denx.de>

Thanks !

Re: [PATCH wireless] wifi: wilc1000: unregister wiphy only if it has been registered

[Kalle Valo]

Marek Vasut <marex@denx.de> writes:

> On 12/23/24 4:46 PM, Alexis Lothoré wrote:
>
>> There is a specific error path in probe functions in wilc drivers (both
>> sdio and spi) which can lead to kernel panic, as this one for example
>> when using SPI:
>> Unable to handle kernel paging request at virtual address 9f000000
>> when read
>> [9f000000] *pgd=00000000
>> Internal error: Oops: 5 [#1] ARM
>> Modules linked in: wilc1000_spi(+) crc_itu_t crc7 wilc1000 cfg80211 bluetooth ecdh_generic ecc
>> CPU: 0 UID: 0 PID: 106 Comm: modprobe Not tainted 6.13.0-rc3+ #22
>> Hardware name: Atmel SAMA5
>> PC is at wiphy_unregister+0x244/0xc40 [cfg80211]
>> LR is at wiphy_unregister+0x1c0/0xc40 [cfg80211]
>> [...]
>>   wiphy_unregister [cfg80211] from wilc_netdev_cleanup+0x380/0x494 [wilc1000]
>>   wilc_netdev_cleanup [wilc1000] from wilc_bus_probe+0x360/0x834 [wilc1000_spi]
>>   wilc_bus_probe [wilc1000_spi] from spi_probe+0x15c/0x1d4
>>   spi_probe from really_probe+0x270/0xb2c
>>   really_probe from __driver_probe_device+0x1dc/0x4e8
>>   __driver_probe_device from driver_probe_device+0x5c/0x140
>>   driver_probe_device from __driver_attach+0x220/0x540
>>   __driver_attach from bus_for_each_dev+0x13c/0x1a8
>>   bus_for_each_dev from bus_add_driver+0x2a0/0x6a4
>>   bus_add_driver from driver_register+0x27c/0x51c
>>   driver_register from do_one_initcall+0xf8/0x564
>>   do_one_initcall from do_init_module+0x2e4/0x82c
>>   do_init_module from load_module+0x59a0/0x70c4
>>   load_module from init_module_from_file+0x100/0x148
>>   init_module_from_file from sys_finit_module+0x2fc/0x924
>>   sys_finit_module from ret_fast_syscall+0x0/0x1c
>> The issue can easily be reproduced, for example by not wiring
>> correctly
>> a wilc device through SPI (and so, make it unresponsive to early SPI
>> commands). It is due to a recent change decoupling wiphy allocation from
>> wiphy registration, however wilc_netdev_cleanup has not been updated
>> accordingly, letting it possibly call wiphy unregister on a wiphy which
>> has never been registered.
>> Fix this crash by moving wiphy_unregister/wiphy_free out of
>> wilc_netdev_cleanup, and by adjusting error paths in both drivers
>> Fixes: fbdf0c5248dc ("wifi: wilc1000: Register wiphy after reading
>> out chipid")
>> Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
> Nice find, thank you for fixing it.
>
> Reviewed-by: Marek Vasut <marex@denx.de>

We are quite late in the cycle so I think I'll queue this to
wireless-next for v6.14.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH wireless] wifi: wilc1000: unregister wiphy only if it has been registered

[Kalle Valo]

Alexis Lothoré <alexis.lothore@bootlin.com> wrote:

> There is a specific error path in probe functions in wilc drivers (both
> sdio and spi) which can lead to kernel panic, as this one for example
> when using SPI:
> 
> Unable to handle kernel paging request at virtual address 9f000000 when read
> [9f000000] *pgd=00000000
> Internal error: Oops: 5 [#1] ARM
> Modules linked in: wilc1000_spi(+) crc_itu_t crc7 wilc1000 cfg80211 bluetooth ecdh_generic ecc
> CPU: 0 UID: 0 PID: 106 Comm: modprobe Not tainted 6.13.0-rc3+ #22
> Hardware name: Atmel SAMA5
> PC is at wiphy_unregister+0x244/0xc40 [cfg80211]
> LR is at wiphy_unregister+0x1c0/0xc40 [cfg80211]
> [...]
>  wiphy_unregister [cfg80211] from wilc_netdev_cleanup+0x380/0x494 [wilc1000]
>  wilc_netdev_cleanup [wilc1000] from wilc_bus_probe+0x360/0x834 [wilc1000_spi]
>  wilc_bus_probe [wilc1000_spi] from spi_probe+0x15c/0x1d4
>  spi_probe from really_probe+0x270/0xb2c
>  really_probe from __driver_probe_device+0x1dc/0x4e8
>  __driver_probe_device from driver_probe_device+0x5c/0x140
>  driver_probe_device from __driver_attach+0x220/0x540
>  __driver_attach from bus_for_each_dev+0x13c/0x1a8
>  bus_for_each_dev from bus_add_driver+0x2a0/0x6a4
>  bus_add_driver from driver_register+0x27c/0x51c
>  driver_register from do_one_initcall+0xf8/0x564
>  do_one_initcall from do_init_module+0x2e4/0x82c
>  do_init_module from load_module+0x59a0/0x70c4
>  load_module from init_module_from_file+0x100/0x148
>  init_module_from_file from sys_finit_module+0x2fc/0x924
>  sys_finit_module from ret_fast_syscall+0x0/0x1c
> 
> The issue can easily be reproduced, for example by not wiring correctly
> a wilc device through SPI (and so, make it unresponsive to early SPI
> commands). It is due to a recent change decoupling wiphy allocation from
> wiphy registration, however wilc_netdev_cleanup has not been updated
> accordingly, letting it possibly call wiphy unregister on a wiphy which
> has never been registered.
> 
> Fix this crash by moving wiphy_unregister/wiphy_free out of
> wilc_netdev_cleanup, and by adjusting error paths in both drivers
> 
> Fixes: fbdf0c5248dc ("wifi: wilc1000: Register wiphy after reading out chipid")
> Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
> Reviewed-by: Marek Vasut <marex@denx.de>

Patch applied to wireless-next.git, thanks.

1be94490b6b8 wifi: wilc1000: unregister wiphy only if it has been registered

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20241223-wilc_fix_probe_error_path-v1-1-91fa7bd8e5b6@bootlin.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches