From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 4 Jul 2022 14:37:11 +0000 (+0200)
Subject: 4.19-stable patches
X-Git-Tag: v4.9.322~39
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a999e26c34466d8373c22613999807c93f74e5dd;p=thirdparty%2Fkernel%2Fstable-queue.git

4.19-stable patches

added patches:
	net-tun-avoid-disabling-napi-twice.patch
---

diff --git a/queue-4.19/net-tun-avoid-disabling-napi-twice.patch b/queue-4.19/net-tun-avoid-disabling-napi-twice.patch
new file mode 100644
index 00000000000..55020a25023
--- /dev/null
+++ b/queue-4.19/net-tun-avoid-disabling-napi-twice.patch
@@ -0,0 +1,41 @@
+From ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5 Mon Sep 17 00:00:00 2001
+From: Jakub Kicinski <kuba@kernel.org>
+Date: Wed, 29 Jun 2022 11:19:10 -0700
+Subject: net: tun: avoid disabling NAPI twice
+
+From: Jakub Kicinski <kuba@kernel.org>
+
+commit ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5 upstream.
+
+Eric reports that syzbot made short work out of my speculative
+fix. Indeed when queue gets detached its tfile->tun remains,
+so we would try to stop NAPI twice with a detach(), close()
+sequence.
+
+Alternative fix would be to move tun_napi_disable() to
+tun_detach_all() and let the NAPI run after the queue
+has been detached.
+
+Fixes: a8fc8cb5692a ("net: tun: stop NAPI when detaching queues")
+Reported-by: syzbot <syzkaller@googlegroups.com>
+Reported-by: Eric Dumazet <edumazet@google.com>
+Reviewed-by: Eric Dumazet <edumazet@google.com>
+Link: https://lore.kernel.org/r/20220629181911.372047-1-kuba@kernel.org
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/tun.c |    3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/drivers/net/tun.c
++++ b/drivers/net/tun.c
+@@ -710,7 +710,8 @@ static void __tun_detach(struct tun_file
+ 	tun = rtnl_dereference(tfile->tun);
+ 
+ 	if (tun && clean) {
+-		tun_napi_disable(tfile);
++		if (!tfile->detached)
++			tun_napi_disable(tfile);
+ 		tun_napi_del(tfile);
+ 	}
+ 
diff --git a/queue-4.19/series b/queue-4.19/series
index b29c061241b..3101d312b2e 100644
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -18,3 +18,4 @@ net-bonding-fix-possible-null-deref-in-rlb-code.patch
 net-bonding-fix-use-after-free-after-802.3ad-slave-unbind.patch
 nfc-nfcmrvl-fix-irq_of_parse_and_map-return-value.patch
 nfc-nxp-nci-don-t-issue-a-zero-length-i2c_master_read.patch
+net-tun-avoid-disabling-napi-twice.patch