From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 24 Mar 2022 12:56:47 +0000 (+0100)
Subject: 5.4-stable patches
X-Git-Tag: v4.9.309~62
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ba9302bf6b1a06080ce727496a921b035c600933;p=thirdparty%2Fkernel%2Fstable-queue.git

5.4-stable patches

added patches:
	net-ipv6-fix-skb_over_panic-in-__ip6_append_data.patch
---

diff --git a/queue-5.4/net-ipv6-fix-skb_over_panic-in-__ip6_append_data.patch b/queue-5.4/net-ipv6-fix-skb_over_panic-in-__ip6_append_data.patch
new file mode 100644
index 00000000000..4607670ffde
--- /dev/null
+++ b/queue-5.4/net-ipv6-fix-skb_over_panic-in-__ip6_append_data.patch
@@ -0,0 +1,47 @@
+From 5e34af4142ffe68f01c8a9acae83300f8911e20c Mon Sep 17 00:00:00 2001
+From: Tadeusz Struk <tadeusz.struk@linaro.org>
+Date: Thu, 10 Mar 2022 15:25:38 -0800
+Subject: net: ipv6: fix skb_over_panic in __ip6_append_data
+
+From: Tadeusz Struk <tadeusz.struk@linaro.org>
+
+commit 5e34af4142ffe68f01c8a9acae83300f8911e20c upstream.
+
+Syzbot found a kernel bug in the ipv6 stack:
+LINK: https://syzkaller.appspot.com/bug?id=205d6f11d72329ab8d62a610c44c5e7e25415580
+The reproducer triggers it by sending a crafted message via sendmmsg()
+call, which triggers skb_over_panic, and crashes the kernel:
+
+skbuff: skb_over_panic: text:ffffffff84647fb4 len:65575 put:65575
+head:ffff888109ff0000 data:ffff888109ff0088 tail:0x100af end:0xfec0
+dev:<NULL>
+
+Update the check that prevents an invalid packet with MTU equal
+to the fregment header size to eat up all the space for payload.
+
+The reproducer can be found here:
+LINK: https://syzkaller.appspot.com/text?tag=ReproC&x=1648c83fb00000
+
+Reported-by: syzbot+e223cf47ec8ae183f2a0@syzkaller.appspotmail.com
+Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
+Acked-by: Willem de Bruijn <willemb@google.com>
+Link: https://lore.kernel.org/r/20220310232538.1044947-1-tadeusz.struk@linaro.org
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/ipv6/ip6_output.c |    4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/net/ipv6/ip6_output.c
++++ b/net/ipv6/ip6_output.c
+@@ -1429,8 +1429,8 @@ static int __ip6_append_data(struct sock
+ 		      sizeof(struct frag_hdr) : 0) +
+ 		     rt->rt6i_nfheader_len;
+ 
+-	if (mtu < fragheaderlen ||
+-	    ((mtu - fragheaderlen) & ~7) + fragheaderlen < sizeof(struct frag_hdr))
++	if (mtu <= fragheaderlen ||
++	    ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr))
+ 		goto emsgsize;
+ 
+ 	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
diff --git a/queue-5.4/series b/queue-5.4/series
index 9b3910aaa24..c87e3e2380c 100644
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -1,3 +1,4 @@
 nfsd-cleanup-nfsd_file_lru_dispose.patch
 nfsd-containerise-filecache-laundrette.patch
 nfc-st21nfca-fix-potential-buffer-overflows-in-evt_transaction.patch
+net-ipv6-fix-skb_over_panic-in-__ip6_append_data.patch