From: Sudeep Holla sudeep.holla@arm.com
[ Upstream commit 9905f728b0bda737fe2c2afd7c24f3365a45cc7b ]
The mhu_db_channel info is allocated per channel using devm_kzalloc from mhu_db_mbox_xlate which gets called from mbox_request_channel. However we are releasing the allocated mhu_db_channel info using plain kfree from mhu_db_shutdown which is called from mbox_free_channel.
This leads to random crashes when the channel is freed like below one:
Unable to handle kernel paging request at virtual address 0080000400000008 [0080000400000008] address between user and kernel address ranges Internal error: Oops: 96000044 [#1] PREEMPT SMP Modules linked in: scmi_module(-) CPU: 1 PID: 2212 Comm: rmmod Not tainted 5.10.0-rc5 #31 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Nov 19 2020 pstate: 20000085 (nzCv daIf -PAN -UAO -TCO BTYPE=--) pc : release_nodes+0x74/0x230 lr : devres_release_all+0x40/0x68 Call trace: release_nodes+0x74/0x230 devres_release_all+0x40/0x68 device_release_driver_internal+0x12c/0x1f8 driver_detach+0x58/0xe8 bus_remove_driver+0x64/0xe0 driver_unregister+0x38/0x68 platform_driver_unregister+0x1c/0x28 scmi_driver_exit+0x38/0x44 [scmi_module] __arm64_sys_delete_module+0x188/0x260 el0_svc_common.constprop.0+0x80/0x1a8 do_el0_svc+0x2c/0x98 el0_sync_handler+0x160/0x168 el0_sync+0x174/0x180 Code: 1400000d eb07009f 54000460 f9400486 (f90004a6) ---[ end trace c55ffd306c140233 ]---
Fix it by replacing kfree with devm_kfree as required.
Fixes: 7002ca237b21 ("mailbox: arm_mhu: Add ARM MHU doorbell driver") Reported-by: Cristian Marussi cristian.marussi@arm.com Signed-off-by: Sudeep Holla sudeep.holla@arm.com Tested-by: Cristian Marussi cristian.marussi@arm.com Reviewed-by: Cristian Marussi cristian.marussi@arm.com Signed-off-by: Jassi Brar jaswinder.singh@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mailbox/arm_mhu_db.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mailbox/arm_mhu_db.c b/drivers/mailbox/arm_mhu_db.c index 275efe4cca0c2..8eb66c4ecf5bf 100644 --- a/drivers/mailbox/arm_mhu_db.c +++ b/drivers/mailbox/arm_mhu_db.c @@ -180,7 +180,7 @@ static void mhu_db_shutdown(struct mbox_chan *chan)
/* Reset channel */ mhu_db_mbox_clear_irq(chan); - kfree(chan->con_priv); + devm_kfree(mbox->dev, chan->con_priv); chan->con_priv = NULL; }