From: Jiri Kosina <jkosina@suse.cz>
Date: Wed, 26 Oct 2011 02:40:39 +0000 (+1030)
Subject: kmod: prevent kmod_loop_msg overflow in __request_module()
X-Git-Tag: firefly_0821_release~3680^2~4316^2~1
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=37252db6aa576c34fd794a5a54fb32d7a8b3a07a;p=firefly-linux-kernel-4.4.55.git

kmod: prevent kmod_loop_msg overflow in __request_module()

Due to post-increment in condition of kmod_loop_msg in __request_module(),
the system log can be spammed by much more than 5 instances of the 'runaway
loop' message if the number of events triggering it makes the kmod_loop_msg
to overflow.

Fix that by making sure we never increment it past the threshold.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: stable@kernel.org
---

diff --git a/kernel/kmod.c b/kernel/kmod.c
index ddc7644c1305..a4bea97c75b6 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -114,10 +114,12 @@ int __request_module(bool wait, const char *fmt, ...)
 	atomic_inc(&kmod_concurrent);
 	if (atomic_read(&kmod_concurrent) > max_modprobes) {
 		/* We may be blaming an innocent here, but unlikely */
-		if (kmod_loop_msg++ < 5)
+		if (kmod_loop_msg < 5) {
 			printk(KERN_ERR
 			       "request_module: runaway loop modprobe %s\n",
 			       module_name);
+			kmod_loop_msg++;
+		}
 		atomic_dec(&kmod_concurrent);
 		return -ENOMEM;
 	}