From 15b17bbcea07d49c43d21aa700485cbd9f9d00d8 Mon Sep 17 00:00:00 2001 From: Xinqi Zhang Date: Wed, 16 Oct 2024 14:13:38 +0800 Subject: [PATCH] firmware: arm_scmi: Fix slab-use-after-free in scmi_bus_notifier() [ Upstream commit 295416091e44806760ccf753aeafdafc0ae268f3 ] The scmi_dev->name is released prematurely in __scmi_device_destroy(), which causes slab-use-after-free when accessing scmi_dev->name in scmi_bus_notifier(). So move the release of scmi_dev->name to scmi_device_release() to avoid slab-use-after-free. | BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec | Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1 | | CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.6.38-debug #1 | Hardware name: Qualcomm Technologies, Inc. SA8775P Ride (DT) | Call trace: | dump_backtrace+0x94/0x114 | show_stack+0x18/0x24 | dump_stack_lvl+0x48/0x60 | print_report+0xf4/0x5b0 | kasan_report+0xa4/0xec | __asan_report_load1_noabort+0x20/0x2c | strncmp+0xe4/0xec | scmi_bus_notifier+0x5c/0x54c | notifier_call_chain+0xb4/0x31c | blocking_notifier_call_chain+0x68/0x9c | bus_notify+0x54/0x78 | device_del+0x1bc/0x840 | device_unregister+0x20/0xb4 | __scmi_device_destroy+0xac/0x280 | scmi_device_destroy+0x94/0xd0 | scmi_chan_setup+0x524/0x750 | scmi_probe+0x7fc/0x1508 | platform_probe+0xc4/0x19c | really_probe+0x32c/0x99c | __driver_probe_device+0x15c/0x3c4 | driver_probe_device+0x5c/0x170 | __driver_attach+0x1c8/0x440 | bus_for_each_dev+0xf4/0x178 | driver_attach+0x3c/0x58 | bus_add_driver+0x234/0x4d4 | driver_register+0xf4/0x3c0 | __platform_driver_register+0x60/0x88 | scmi_driver_init+0xb0/0x104 | do_one_initcall+0xb4/0x664 | kernel_init_freeable+0x3c8/0x894 | kernel_init+0x24/0x1e8 | ret_from_fork+0x10/0x20 | | Allocated by task 1: | kasan_save_stack+0x2c/0x54 | kasan_set_track+0x2c/0x40 | kasan_save_alloc_info+0x24/0x34 | __kasan_kmalloc+0xa0/0xb8 | __kmalloc_node_track_caller+0x6c/0x104 | kstrdup+0x48/0x84 | kstrdup_const+0x34/0x40 | __scmi_device_create.part.0+0x8c/0x408 | scmi_device_create+0x104/0x370 | scmi_chan_setup+0x2a0/0x750 | scmi_probe+0x7fc/0x1508 | platform_probe+0xc4/0x19c | really_probe+0x32c/0x99c | __driver_probe_device+0x15c/0x3c4 | driver_probe_device+0x5c/0x170 | __driver_attach+0x1c8/0x440 | bus_for_each_dev+0xf4/0x178 | driver_attach+0x3c/0x58 | bus_add_driver+0x234/0x4d4 | driver_register+0xf4/0x3c0 | __platform_driver_register+0x60/0x88 | scmi_driver_init+0xb0/0x104 | do_one_initcall+0xb4/0x664 | kernel_init_freeable+0x3c8/0x894 | kernel_init+0x24/0x1e8 | ret_from_fork+0x10/0x20 | | Freed by task 1: | kasan_save_stack+0x2c/0x54 | kasan_set_track+0x2c/0x40 | kasan_save_free_info+0x38/0x5c | __kasan_slab_free+0xe8/0x164 | __kmem_cache_free+0x11c/0x230 | kfree+0x70/0x130 | kfree_const+0x20/0x40 | __scmi_device_destroy+0x70/0x280 | scmi_device_destroy+0x94/0xd0 | scmi_chan_setup+0x524/0x750 | scmi_probe+0x7fc/0x1508 | platform_probe+0xc4/0x19c | really_probe+0x32c/0x99c | __driver_probe_device+0x15c/0x3c4 | driver_probe_device+0x5c/0x170 | __driver_attach+0x1c8/0x440 | bus_for_each_dev+0xf4/0x178 | driver_attach+0x3c/0x58 | bus_add_driver+0x234/0x4d4 | driver_register+0xf4/0x3c0 | __platform_driver_register+0x60/0x88 | scmi_driver_init+0xb0/0x104 | do_one_initcall+0xb4/0x664 | kernel_init_freeable+0x3c8/0x894 | kernel_init+0x24/0x1e8 | ret_from_fork+0x10/0x20 Fixes: ee7a9c9f67c5 ("firmware: arm_scmi: Add support for multiple device per protocol") Signed-off-by: Xinqi Zhang Reviewed-by: Cristian Marussi Reviewed-by: Bjorn Andersson Message-Id: <20241016-fix-arm-scmi-slab-use-after-free-v2-1-1783685ef90d@quicinc.com> Signed-off-by: Sudeep Holla Signed-off-by: Sasha Levin --- drivers/firmware/arm_scmi/bus.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c index c15928b8c5cc9..dcf774d3edfe4 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -305,7 +305,10 @@ EXPORT_SYMBOL_GPL(scmi_driver_unregister); static void scmi_device_release(struct device *dev) { - kfree(to_scmi_dev(dev)); + struct scmi_device *scmi_dev = to_scmi_dev(dev); + + kfree_const(scmi_dev->name); + kfree(scmi_dev); } static void __scmi_device_destroy(struct scmi_device *scmi_dev) @@ -318,7 +321,6 @@ static void __scmi_device_destroy(struct scmi_device *scmi_dev) if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM) atomic_set(&scmi_syspower_registered, 0); - kfree_const(scmi_dev->name); ida_free(&scmi_bus_id, scmi_dev->id); device_unregister(&scmi_dev->dev); } @@ -390,7 +392,6 @@ __scmi_device_create(struct device_node *np, struct device *parent, return scmi_dev; put_dev: - kfree_const(scmi_dev->name); put_device(&scmi_dev->dev); ida_free(&scmi_bus_id, id); return NULL;