netdev - [PATCH net V3 2/2] ptr_ring: fail on large queue size (>64K)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1518062365-8596-2-git-send-email-jasowang@redhat.com>
Date:   Thu,  8 Feb 2018 11:59:25 +0800
From:   Jason Wang <jasowang@...hat.com>
To:     mst@...hat.com
Cc:     netdev@...r.kernel.org, Jason Wang <jasowang@...hat.com>
Subject: [PATCH net V3 2/2] ptr_ring: fail on large queue size (>64K)

We need limit the maximum size of queue, otherwise it may cause
several side effects e.g slab will warn when the size exceeds
KMALLOC_MAX_SIZE. Using KMALLOC_MAX_SIZE still looks too so this patch
tries to limit it to 64K. This value could be revisited if we found a
real case that needs more.

Reported-by: syzbot+e4d4f9ddd4295539735d@...kaller.appspotmail.com
Fixes: 2e0ab8ca83c12 ("ptr_ring: array based FIFO for pointers")
Signed-off-by: Jason Wang <jasowang@...hat.com>
---
 include/linux/ptr_ring.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index 2af71a7..5858d48 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -44,6 +44,8 @@ struct ptr_ring {
 	void **queue;
 };
 
+#define PTR_RING_MAX_ALLOC 65536
+
 /* Note: callers invoking this in a loop must use a compiler barrier,
  * for example cpu_relax().
  *
@@ -466,6 +468,8 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r,
 
 static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp)
 {
+	if (size > PTR_RING_MAX_ALLOC)
+		return NULL;
 	return kvmalloc_array(size, sizeof(void *), gfp | __GFP_ZERO);
 }
 
-- 
2.7.4