From: Venkata Narendra Kumar Gutta vnkgutta@codeaurora.org
[ Upstream commit edb16da34b084c66763f29bee42b4e6bb33c3d66 ]
Platform core is using pdev->name as the platform device name to do the binding of the devices with the drivers. But, when the platform driver overrides the platform device name with dev_set_name(), the pdev->name is pointing to a location which is freed and becomes an invalid parameter to do the binding match.
use-after-free instance:
[ 33.325013] BUG: KASAN: use-after-free in strcmp+0x8c/0xb0 [ 33.330646] Read of size 1 at addr ffffffc10beae600 by task modprobe [ 33.339068] CPU: 5 PID: 518 Comm: modprobe Tainted: G S W O 4.19.30+ #3 [ 33.346835] Hardware name: MTP (DT) [ 33.350419] Call trace: [ 33.352941] dump_backtrace+0x0/0x3b8 [ 33.356713] show_stack+0x24/0x30 [ 33.360119] dump_stack+0x160/0x1d8 [ 33.363709] print_address_description+0x84/0x2e0 [ 33.368549] kasan_report+0x26c/0x2d0 [ 33.372322] __asan_report_load1_noabort+0x2c/0x38 [ 33.377248] strcmp+0x8c/0xb0 [ 33.380306] platform_match+0x70/0x1f8 [ 33.384168] __driver_attach+0x78/0x3a0 [ 33.388111] bus_for_each_dev+0x13c/0x1b8 [ 33.392237] driver_attach+0x4c/0x58 [ 33.395910] bus_add_driver+0x350/0x560 [ 33.399854] driver_register+0x23c/0x328 [ 33.403886] __platform_driver_register+0xd0/0xe0
So, use dev_name(&pdev->dev), which fetches the platform device name from the kobject(dev->kobj->name) of the device instead of the pdev->name.
Signed-off-by: Venkata Narendra Kumar Gutta vnkgutta@codeaurora.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/platform.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 9045c5f3734e8..080038bbed39b 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -855,7 +855,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *a, if (len != -ENODEV) return len;
- len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name); + len = snprintf(buf, PAGE_SIZE, "platform:%s\n", dev_name(&pdev->dev));
return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len; } @@ -931,7 +931,7 @@ static int platform_uevent(struct device *dev, struct kobj_uevent_env *env) return rc;
add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX, - pdev->name); + dev_name(&pdev->dev)); return 0; }
@@ -940,7 +940,7 @@ static const struct platform_device_id *platform_match_id( struct platform_device *pdev) { while (id->name[0]) { - if (strcmp(pdev->name, id->name) == 0) { + if (strcmp(dev_name(&pdev->dev), id->name) == 0) { pdev->id_entry = id; return id; } @@ -984,7 +984,7 @@ static int platform_match(struct device *dev, struct device_driver *drv) return platform_match_id(pdrv->id_table, pdev) != NULL;
/* fall-back to driver name match */ - return (strcmp(pdev->name, drv->name) == 0); + return (strcmp(dev_name(&pdev->dev), drv->name) == 0); }
#ifdef CONFIG_PM_SLEEP