In an event where the platform running the device control plane
is rebooted, reset is detected on the driver. It releases
all the resources and waits for the reset to complete. Once the
reset is done, it tries to build the resources back. At this
time if the device control plane is not yet started, then
the driver timeouts on the virtchnl message and retries to
establish the mailbox again.
In the retry flow, mailbox is deinitialized but the mailbox
workqueue is still alive and polling for the mailbox message.
This results in accessing the released control queue leading to
null-ptr-deref. Fix it by unrolling the work queue cancellation
and mailbox deinitialization in the reverse order which they got
initialized.
Fixes: 4930fbf419a7 ("idpf: add core init and interrupt request")
Fixes: 34c21fa894a1 ("idpf: implement virtchnl transaction manager")
Cc: stable(a)vger.kernel.org # 6.9+
Reviewed-by: Tarun K Singh <tarun.k.singh(a)intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga(a)intel.com>
---
v2:
- remove changes which are not fixes for the actual issue from this patch
---
drivers/net/ethernet/intel/idpf/idpf_lib.c | 1 +
drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 1 -
2 files changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index c3848e10e7db..b4fbb99bfad2 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -1786,6 +1786,7 @@ static int idpf_init_hard_reset(struct idpf_adapter *adapter)
*/
err = idpf_vc_core_init(adapter);
if (err) {
+ cancel_delayed_work_sync(&adapter->mbx_task);
idpf_deinit_dflt_mbx(adapter);
goto unlock_mutex;
}
diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
index 3be883726b87..e7eee571d908 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
@@ -3070,7 +3070,6 @@ int idpf_vc_core_init(struct idpf_adapter *adapter)
adapter->state = __IDPF_VER_CHECK;
if (adapter->vcxn_mngr)
idpf_vc_xn_shutdown(adapter->vcxn_mngr);
- idpf_deinit_dflt_mbx(adapter);
set_bit(IDPF_HR_DRV_LOAD, adapter->flags);
queue_delayed_work(adapter->vc_event_wq, &adapter->vc_event_task,
msecs_to_jiffies(task_delay));
--
2.43.0
If the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is
fully initialized, we can hit the panic below:
hv_utils: Registering HyperV Utility Driver
hv_vmbus: registering driver hv_utils
...
BUG: kernel NULL pointer dereference, address: 0000000000000000
CPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1
RIP: 0010:hv_pkt_iter_first+0x12/0xd0
Call Trace:
...
vmbus_recvpacket
hv_kvp_onchannelcallback
vmbus_on_event
tasklet_action_common
tasklet_action
handle_softirqs
irq_exit_rcu
sysvec_hyperv_stimer0
</IRQ>
<TASK>
asm_sysvec_hyperv_stimer0
...
kvp_register_done
hvt_op_read
vfs_read
ksys_read
__x64_sys_read
This can happen because the KVP/VSS channel callback can be invoked
even before the channel is fully opened:
1) as soon as hv_kvp_init() -> hvutil_transport_init() creates
/dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and
register itself to the driver by writing a message KVP_OP_REGISTER1 to the
file (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and
reading the file for the driver's response, which is handled by
hvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done().
2) the problem with kvp_register_done() is that it can cause the
channel callback to be called even before the channel is fully opened,
and when the channel callback is starting to run, util_probe()->
vmbus_open() may have not initialized the ringbuffer yet, so the
callback can hit the panic of NULL pointer dereference.
To reproduce the panic consistently, we can add a "ssleep(10)" for KVP in
__vmbus_open(), just before the first hv_ringbuffer_init(), and then we
unload and reload the driver hv_utils, and run the daemon manually within
the 10 seconds.
Fix the panic by checking the channel state in the channel callback.
To avoid the race condition with __vmbus_open(), we disable and enable
the channel callback temporarily in __vmbus_open().
The channel callbacks of the other VMBus devices don't need to check
the channel state since they can't run before the channels are fully
initialized.
Note: we would also need to fix the fcopy driver code, but that has
been removed in commit ec314f61e4fc ("Drivers: hv: Remove fcopy driver") in
the mainline kernel since v6.10. For old 6.x LTS kernels, and the 5.x
and 4.x LTS kernels, the fcopy driver needs to be fixed when the
fix is backported to the stable kernel branches.
Fixes: e0fa3e5e7df6 ("Drivers: hv: utils: fix a race on userspace daemons registration")
Cc: stable(a)vger.kernel.org
Signed-off-by: Dexuan Cui <decui(a)microsoft.com>
---
drivers/hv/channel.c | 11 +++++++++++
drivers/hv/hv_kvp.c | 3 +++
drivers/hv/hv_snapshot.c | 3 +++
3 files changed, 17 insertions(+)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index fb8cd8469328..685e407a3fdf 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -657,6 +657,14 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
return -ENOMEM;
}
+ /*
+ * The channel callbacks of KVP/VSS may run before __vmbus_open()
+ * finishes (see kvp_register_done() -> ... -> kvp_poll_wrapper()), so
+ * they check newchannel->state to tell the ringbuffer has been fully
+ * initialized or not. Disable and enable the tasklet to avoid the race.
+ */
+ tasklet_disable(&newchannel->callback_event);
+
newchannel->state = CHANNEL_OPENING_STATE;
newchannel->onchannel_callback = onchannelcallback;
newchannel->channel_callback_context = context;
@@ -750,6 +758,8 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
}
newchannel->state = CHANNEL_OPENED_STATE;
+ tasklet_enable(&newchannel->callback_event);
+
kfree(open_info);
return 0;
@@ -766,6 +776,7 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
hv_ringbuffer_cleanup(&newchannel->inbound);
vmbus_free_requestor(&newchannel->requestor);
newchannel->state = CHANNEL_OPEN_STATE;
+ tasklet_enable(&newchannel->callback_event);
return err;
}
diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index d35b60c06114..ec098067e579 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -662,6 +662,9 @@ void hv_kvp_onchannelcallback(void *context)
if (kvp_transaction.state > HVUTIL_READY)
return;
+ if (channel->state != CHANNEL_OPENED_STATE)
+ return;
+
if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 4, &recvlen, &requestid)) {
pr_err_ratelimited("KVP request received. Could not read into recv buf\n");
return;
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index 0d2184be1691..f7924c2fc62e 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -301,6 +301,9 @@ void hv_vss_onchannelcallback(void *context)
if (vss_transaction.state > HVUTIL_READY)
return;
+ if (channel->state != CHANNEL_OPENED_STATE)
+ return;
+
if (vmbus_recvpacket(channel, recv_buffer, VSS_MAX_PKT_SIZE, &recvlen, &requestid)) {
pr_err_ratelimited("VSS request received. Could not read into recv buf\n");
return;
--
2.25.1
Syzkaller reported a hung task with uevent_show() on stack trace. That
specific issue was addressed by another commit [0], but even with that
fix applied (for example, running v6.12-rc5) we face another type of hung
task that comes from the same reproducer [1]. By investigating that, we
could narrow it to the following path:
(a) Syzkaller emulates a Realtek USB WiFi adapter using raw-gadget and
dummy_hcd infrastructure.
(b) During the probe of rtl8192cu, the driver ends-up performing an efuse
read procedure (which is related to EEPROM load IIUC), and here lies the
issue: the function read_efuse() calls read_efuse_byte() many times, as
loop iterations depending on the efuse size (in our example, 512 in total).
This procedure for reading efuse bytes relies in a loop that performs an
I/O read up to *10k* times in case of failures. We measured the time of
the loop inside read_efuse_byte() alone, and in this reproducer (which
involves the dummy_hcd emulation layer), it takes 15 seconds each. As a
consequence, we have the driver stuck in its probe routine for big time,
exposing a stack trace like below if we attempt to reboot the system, for
example:
task:kworker/0:3 state:D stack:0 pid:662 tgid:662 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
__schedule+0xe22/0xeb6
schedule_timeout+0xe7/0x132
__wait_for_common+0xb5/0x12e
usb_start_wait_urb+0xc5/0x1ef
? usb_alloc_urb+0x95/0xa4
usb_control_msg+0xff/0x184
_usbctrl_vendorreq_sync+0xa0/0x161
_usb_read_sync+0xb3/0xc5
read_efuse_byte+0x13c/0x146
read_efuse+0x351/0x5f0
efuse_read_all_map+0x42/0x52
rtl_efuse_shadow_map_update+0x60/0xef
rtl_get_hwinfo+0x5d/0x1c2
rtl92cu_read_eeprom_info+0x10a/0x8d5
? rtl92c_read_chip_version+0x14f/0x17e
rtl_usb_probe+0x323/0x851
usb_probe_interface+0x278/0x34b
really_probe+0x202/0x4a4
__driver_probe_device+0x166/0x1b2
driver_probe_device+0x2f/0xd8
[...]
We propose hereby to drastically reduce the attempts of doing the I/O reads
in case of failures, restricted to USB devices (given that they're inherently
slower than PCIe ones). By retrying up to 10 times (instead of 10000), we
got reponsiveness in the reproducer, while seems reasonable to believe
that there's no sane USB device implementation in the field requiring this
amount of retries at every I/O read in order to properly work. Based on
that assumption, it'd be good to have it backported to stable but maybe not
since driver implementation (the 10k number comes from day 0), perhaps up
to 6.x series makes sense.
[0] Commit 15fffc6a5624 ("driver core: Fix uevent_show() vs driver detach race").
[1] A note about that: this syzkaller report presents multiple reproducers
that differs by the type of emulated USB device. For this specific case,
check the entry from 2024/08/08 06:23 in the list of crashes; the C repro
is available at https://syzkaller.appspot.com/text?tag=ReproC&x=1521fc83980000.
Cc: stable(a)vger.kernel.org # v6.1+
Reported-by: syzbot+edd9fe0d3a65b14588d5(a)syzkaller.appspotmail.com
Signed-off-by: Guilherme G. Piccoli <gpiccoli(a)igalia.com>
---
V3:
- Switch variable declaration to reverse xmas tree order
(thanks Ping-Ke Shih for the suggestion).
V2:
- Restrict the change to USB device only (thanks Ping-Ke Shih).
- Tested in 2 USB devices by Bitterblue Smith - thanks a lot!
V1: https://lore.kernel.org/lkml/20241025150226.896613-1-gpiccoli@igalia.com/
drivers/net/wireless/realtek/rtlwifi/efuse.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtlwifi/efuse.c b/drivers/net/wireless/realtek/rtlwifi/efuse.c
index 82cf5fb5175f..0ff553f650f9 100644
--- a/drivers/net/wireless/realtek/rtlwifi/efuse.c
+++ b/drivers/net/wireless/realtek/rtlwifi/efuse.c
@@ -162,9 +162,19 @@ void efuse_write_1byte(struct ieee80211_hw *hw, u16 address, u8 value)
void read_efuse_byte(struct ieee80211_hw *hw, u16 _offset, u8 *pbuf)
{
struct rtl_priv *rtlpriv = rtl_priv(hw);
+ u16 retry, max_attempts;
u32 value32;
u8 readbyte;
- u16 retry;
+
+ /*
+ * In case of USB devices, transfer speeds are limited, hence
+ * efuse I/O reads could be (way) slower. So, decrease (a lot)
+ * the read attempts in case of failures.
+ */
+ if (rtlpriv->rtlhal.interface == INTF_PCI)
+ max_attempts = 10000;
+ else
+ max_attempts = 10;
rtl_write_byte(rtlpriv, rtlpriv->cfg->maps[EFUSE_CTRL] + 1,
(_offset & 0xff));
@@ -178,7 +188,7 @@ void read_efuse_byte(struct ieee80211_hw *hw, u16 _offset, u8 *pbuf)
retry = 0;
value32 = rtl_read_dword(rtlpriv, rtlpriv->cfg->maps[EFUSE_CTRL]);
- while (!(((value32 >> 24) & 0xff) & 0x80) && (retry < 10000)) {
+ while (!(((value32 >> 24) & 0xff) & 0x80) && (retry < max_attempts)) {
value32 = rtl_read_dword(rtlpriv,
rtlpriv->cfg->maps[EFUSE_CTRL]);
retry++;
--
2.46.2
From: MrRurikov <grurikov(a)gmal.com>
After having been assigned to a NULL value at rdma.c:1758, pointer 'queue'
is passed as 1st parameter in call to function
'nvmet_rdma_queue_established' at rdma.c:1773, as 1st parameter in call
to function 'nvmet_rdma_queue_disconnect' at rdma.c:1787 and as 2nd
parameter in call to function 'nvmet_rdma_queue_connect_fail' at
rdma.c:1800, where it is dereferenced.
I understand, that driver is confident that the
RDMA_CM_EVENT_CONNECT_REQUEST event will occur first and perform
initialization, but maliciously prepared hardware could send events in
violation of the protocol. Nothing guarantees that the sequence of events
will start with RDMA_CM_EVENT_CONNECT_REQUEST.
Found by Linux Verification Center (linuxtesting.org) with SVACE
Fixes: e1a2ee249b19 ("nvmet-rdma: Fix use after free in nvmet_rdma_cm_handler()")
Cc: stable(a)vger.kernel.org
Signed-off-by: George Rurikov <g.ryurikov(a)securitycode.ru>
---
drivers/nvme/target/rdma.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 1b6264fa5803..becebc95f349 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -1770,8 +1770,10 @@ static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
ret = nvmet_rdma_queue_connect(cm_id, event);
break;
case RDMA_CM_EVENT_ESTABLISHED:
- nvmet_rdma_queue_established(queue);
- break;
+ if (!queue) {
+ nvmet_rdma_queue_established(queue);
+ break;
+ }
case RDMA_CM_EVENT_ADDR_CHANGE:
if (!queue) {
struct nvmet_rdma_port *port = cm_id->context;
@@ -1782,8 +1784,10 @@ static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
fallthrough;
case RDMA_CM_EVENT_DISCONNECTED:
case RDMA_CM_EVENT_TIMEWAIT_EXIT:
- nvmet_rdma_queue_disconnect(queue);
- break;
+ if (!queue) {
+ nvmet_rdma_queue_disconnect(queue);
+ break;
+ }
case RDMA_CM_EVENT_DEVICE_REMOVAL:
ret = nvmet_rdma_device_removal(cm_id, queue);
break;
@@ -1793,8 +1797,10 @@ static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
fallthrough;
case RDMA_CM_EVENT_UNREACHABLE:
case RDMA_CM_EVENT_CONNECT_ERROR:
- nvmet_rdma_queue_connect_fail(cm_id, queue);
- break;
+ if (!queue) {
+ nvmet_rdma_queue_connect_fail(cm_id, queue);
+ break;
+ }
default:
pr_err("received unrecognized RDMA CM event %d\n",
event->event);
--
2.34.1
The assignment of the of_node to the aux bridge needs to mark the
of_node as reused as well, otherwise resource providers like pinctrl will
report a gpio as already requested by a different device when both pinconf
and gpios property are present.
Fix that by using the device_set_of_node_from_dev() helper instead.
Fixes: 6914968a0b52 ("drm/bridge: properly refcount DT nodes in aux bridge drivers")
Cc: stable(a)vger.kernel.org # 6.8
Cc: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org>
Signed-off-by: Abel Vesa <abel.vesa(a)linaro.org>
---
Changes in v2:
- Re-worded commit to be more explicit of what it fixes, as Johan suggested
- Used device_set_of_node_from_dev() helper, as per Johan's suggestion
- Added Fixes tag and cc'ed stable
- Link to v1: https://lore.kernel.org/r/20241017-drm-aux-bridge-mark-of-node-reused-v1-1-…
---
drivers/gpu/drm/bridge/aux-bridge.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/aux-bridge.c b/drivers/gpu/drm/bridge/aux-bridge.c
index b29980f95379ec7af873ed6e0fb79a9abb663c7b..295e9d031e2dc86cbfd2a7350718fca181c99487 100644
--- a/drivers/gpu/drm/bridge/aux-bridge.c
+++ b/drivers/gpu/drm/bridge/aux-bridge.c
@@ -58,9 +58,10 @@ int drm_aux_bridge_register(struct device *parent)
adev->id = ret;
adev->name = "aux_bridge";
adev->dev.parent = parent;
- adev->dev.of_node = of_node_get(parent->of_node);
adev->dev.release = drm_aux_bridge_release;
+ device_set_of_node_from_dev(&adev->dev, parent);
+
ret = auxiliary_device_init(adev);
if (ret) {
ida_free(&drm_aux_bridge_ida, adev->id);
---
base-commit: d61a00525464bfc5fe92c6ad713350988e492b88
change-id: 20241017-drm-aux-bridge-mark-of-node-reused-5c2ee740ff19
Best regards,
--
Abel Vesa <abel.vesa(a)linaro.org>
The unsigned variable `size_t len` is cast to the signed type `loff_t`
when passed to the function check_add_overflow(). This function considers
the type of the destination, which is of type loff_t (signed),
potentially leading to an overflow. This issue is similar to the one
described in the link below.
Remove the cast.
Note that even if check_add_overflow() is bypassed, by setting `len` to
a value that is greater than LONG_MAX (which is considered as a negative
value after the cast), the function copy_from_user(), invoked a few lines
later, will not perform any copy and return `len` as (len > INT_MAX)
causing qat_vf_resume_write() to fail with -EFAULT.
Fixes: bb208810b1ab ("vfio/qat: Add vfio_pci driver for Intel QAT SR-IOV VF devices")
CC: stable(a)vger.kernel.org # 6.10+
Link: https://lore.kernel.org/all/138bd2e2-ede8-4bcc-aa7b-f3d9de167a37@moroto.mou…
Reported-by: Zijie Zhao <zzjas98(a)gmail.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu(a)intel.com>
Reviewed-by: Xin Zeng <xin.zeng(a)intel.com>
---
drivers/vfio/pci/qat/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/vfio/pci/qat/main.c b/drivers/vfio/pci/qat/main.c
index e36740a282e7..1e3563fe7cab 100644
--- a/drivers/vfio/pci/qat/main.c
+++ b/drivers/vfio/pci/qat/main.c
@@ -305,7 +305,7 @@ static ssize_t qat_vf_resume_write(struct file *filp, const char __user *buf,
offs = &filp->f_pos;
if (*offs < 0 ||
- check_add_overflow((loff_t)len, *offs, &end))
+ check_add_overflow(len, *offs, &end))
return -EOVERFLOW;
if (end > mig_dev->state_size)
--
2.47.0
Device nodes accessed via of_get_compatible_child() require
of_node_put() to be called when the node is no longer required to avoid
leaving a reference to the node behind, leaking the resource.
In this case, the usage of 'tnode' is straightforward and there are no
error paths, allowing for a single of_node_put() when 'tnode' is no
longer required.
Cc: stable(a)vger.kernel.org
Fixes: 29646ee33cc3 ("counter: stm32-timer-cnt: add checks on quadrature encoder capability")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz(a)gmail.com>
---
drivers/counter/stm32-timer-cnt.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index 186e73d6ccb4..0d8206adccb3 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -694,6 +694,7 @@ static int stm32_timer_cnt_probe_encoder(struct device *dev,
}
ret = of_property_read_u32(tnode, "reg", &idx);
+ of_node_put(tnode);
if (ret) {
dev_err(dev, "Can't get index (%d)\n", ret);
return ret;
---
base-commit: a39230ecf6b3057f5897bc4744a790070cfbe7a8
change-id: 20241027-stm32-timer-cnt-of_node_put-8c6695e7a373
Best regards,
--
Javier Carrasco <javier.carrasco.cruz(a)gmail.com>