[PATCH] netnode.c : fix sel_netnode_hash be destroyed

From: hui yang
Date: Fri Dec 20 2019 - 05:07:38 EST


From: YangHui <yanghui.def@xxxxxxxxx>

we often find below error :
[ 30.729718] Unable to handle kernel paging request at virtual address fffffffffffffffc
[ 30.747478] Kernel BUG at sel_netnode_find+0x6c/0xf0 [verbose debug info unavailable]
[ 30.818858] PC is at sel_netnode_find+0x6c/0xf0
[ 30.824671] LR is at sel_netnode_sid+0x3c/0x248
[ 30.829170] pc : [<ffffff8008428094>] lr : [<ffffff8008428154>] pstate: a0400145
[ 30.833701] sp : ffffffc026f27c50
[ 30.841319] x29: ffffffc026f27c50 x28: ffffffc026f27e40
[ 30.849634] x27: ffffff8009132000 x26: 0000000000000000
[ 30.854932] x25: ffffffc016f0aa80 x24: 0000000000000000
[ 30.860224] x23: ffffffc026f27e38 x22: ffffffc026f27d34
[ 30.865520] x21: 000000000000000a x20: ffffffc026f27e40
[ 30.870818] x19: 000000000000000a x18: 0000007a13b48000
[ 30.876118] x17: 0000007a16ca93c0 x16: ffffff8008e56b2c
[ 30.881406] x15: 0000000000000020 x14: 002dc6bffa5d9e00
[ 30.886701] x13: 203a644974654e4c x12: 00000000000017c1
[ 30.891997] x11: 0000000000000000 x10: 0000000000000001
[ 30.897292] x9 : 0000000000000002 x8 : ffffff8009933090
[ 30.902588] x7 : ffffffc0725fd090 x6 : 0000000004fd9f2c
[ 30.907881] x5 : 0000000000000000 x4 : 0000000000000000
[ 30.913176] x3 : 00000001ffffffff x2 : 0000000000000000
[ 30.918475] x1 : ffffff800a10ca80 x0 : ffffffffffffffe8
some sel_netnode_hash[idx].list==NULL,so happend this.
I add spin_lock_bh on sel_netnode_init.

Signed-off-by: YangHui <yanghui.def@xxxxxxxxx>
---
security/selinux/netnode.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/selinux/netnode.c b/security/selinux/netnode.c
index 9ab84ef..aa0eeb7 100644
--- a/security/selinux/netnode.c
+++ b/security/selinux/netnode.c
@@ -293,11 +293,12 @@ static __init int sel_netnode_init(void)

if (!selinux_enabled)
return 0;
-
+ spin_lock_bh(&sel_netnode_lock);
for (iter = 0; iter < SEL_NETNODE_HASH_SIZE; iter++) {
INIT_LIST_HEAD(&sel_netnode_hash[iter].list);
sel_netnode_hash[iter].size = 0;
}
+ spin_unlock_bh(&sel_netnode_lock);

return 0;
}
--
2.7.4