DivestOS/Patches/Linux_CVEs/CVE-2017-6348/^4.9/0001.patch
2017-11-07 17:32:46 -05:00

88 lines
2.6 KiB
Diff

From 4c03b862b12f980456f9de92db6d508a4999b788 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Fri, 17 Feb 2017 16:19:39 -0500
Subject: irda: Fix lockdep annotations in hashbin_delete().
A nested lock depth was added to the hasbin_delete() code but it
doesn't actually work some well and results in tons of lockdep splats.
Fix the code instead to properly drop the lock around the operation
and just keep peeking the head of the hashbin queue.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/irda/irqueue.c | 34 ++++++++++++++++------------------
1 file changed, 16 insertions(+), 18 deletions(-)
diff --git a/net/irda/irqueue.c b/net/irda/irqueue.c
index acbe61c..160dc89 100644
--- a/net/irda/irqueue.c
+++ b/net/irda/irqueue.c
@@ -383,9 +383,6 @@ EXPORT_SYMBOL(hashbin_new);
* for deallocating this structure if it's complex. If not the user can
* just supply kfree, which should take care of the job.
*/
-#ifdef CONFIG_LOCKDEP
-static int hashbin_lock_depth = 0;
-#endif
int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func)
{
irda_queue_t* queue;
@@ -396,22 +393,27 @@ int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func)
IRDA_ASSERT(hashbin->magic == HB_MAGIC, return -1;);
/* Synchronize */
- if ( hashbin->hb_type & HB_LOCK ) {
- spin_lock_irqsave_nested(&hashbin->hb_spinlock, flags,
- hashbin_lock_depth++);
- }
+ if (hashbin->hb_type & HB_LOCK)
+ spin_lock_irqsave(&hashbin->hb_spinlock, flags);
/*
* Free the entries in the hashbin, TODO: use hashbin_clear when
* it has been shown to work
*/
for (i = 0; i < HASHBIN_SIZE; i ++ ) {
- queue = dequeue_first((irda_queue_t**) &hashbin->hb_queue[i]);
- while (queue ) {
- if (free_func)
- (*free_func)(queue);
- queue = dequeue_first(
- (irda_queue_t**) &hashbin->hb_queue[i]);
+ while (1) {
+ queue = dequeue_first((irda_queue_t**) &hashbin->hb_queue[i]);
+
+ if (!queue)
+ break;
+
+ if (free_func) {
+ if (hashbin->hb_type & HB_LOCK)
+ spin_unlock_irqrestore(&hashbin->hb_spinlock, flags);
+ free_func(queue);
+ if (hashbin->hb_type & HB_LOCK)
+ spin_lock_irqsave(&hashbin->hb_spinlock, flags);
+ }
}
}
@@ -420,12 +422,8 @@ int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func)
hashbin->magic = ~HB_MAGIC;
/* Release lock */
- if ( hashbin->hb_type & HB_LOCK) {
+ if (hashbin->hb_type & HB_LOCK)
spin_unlock_irqrestore(&hashbin->hb_spinlock, flags);
-#ifdef CONFIG_LOCKDEP
- hashbin_lock_depth--;
-#endif
- }
/*
* Free the hashbin structure
--
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