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authorSabrina Dubroca <sd@queasysnail.net>2017-12-31 16:18:56 +0100
committerSteffen Klassert <steffen.klassert@secunet.com>2017-12-31 16:29:24 +0100
commit2f10a61cee8fdb9f8da90f5db687e1862b22cf06 (patch)
treece6216dcf1b159f1c63a130778fe81105a3bd8fb /net/xfrm
parent4e765b4972af7b07adcb1feb16e7a525ce1f6b28 (diff)
downloadlinux-2f10a61cee8fdb9f8da90f5db687e1862b22cf06.tar.bz2
xfrm: fix rcu usage in xfrm_get_type_offload
request_module can sleep, thus we cannot hold rcu_read_lock() while calling it. The function also jumps back and takes rcu_read_lock() again (in xfrm_state_get_afinfo()), resulting in an imbalance. This codepath is triggered whenever a new offloaded state is created. Fixes: ffdb5211da1c ("xfrm: Auto-load xfrm offload modules") Reported-by: syzbot+ca425f44816d749e8eb49755567a75ee48cf4a30@syzkaller.appspotmail.com Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm')
-rw-r--r--net/xfrm/xfrm_state.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 1e80f68e2266..429957412633 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -313,13 +313,14 @@ retry:
if ((type && !try_module_get(type->owner)))
type = NULL;
+ rcu_read_unlock();
+
if (!type && try_load) {
request_module("xfrm-offload-%d-%d", family, proto);
try_load = 0;
goto retry;
}
- rcu_read_unlock();
return type;
}