driver core: platform: Add extra error check in devm_platform_get_irqs_affinity()

mainline inclusion
from mainline-v5.11-rc5
commit e1dc2099
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6LM81
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e1dc20995cb9fa04b46e8f37113a7203c906d2bf

---------------------------------------------

The current check of nvec < minvec for nvec returned from
platform_irq_count() will not detect a negative error code in nvec.

This is because minvec is unsigned, and, as such, nvec is promoted to
unsigned in that check, which will make it a huge number (if it contained
-EPROBE_DEFER).

In practice, an error should not occur in nvec for the only in-tree
user, but add a check anyway.

Fixes: e15f2fa9 ("driver core: platform: Add devm_platform_get_irqs_affinity()")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1608561055-231244-1-git-send-email-john.garry@huawei.comSigned-off-by: NZhang Zekun <zhangzekun11@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

drivers/base/platform.c

@@ -351,6 +351,8 @@ int devm_platform_get_irqs_affinity(struct platform_device *dev,
 		return -ERANGE;
 
 	nvec = platform_irq_count(dev);
+	if (nvec < 0)
+		return nvec;
 
 	if (nvec < minvec)
 		return -ENOSPC;