[PATCH AUTOSEL 4.4 35/35] net: fix NULL pointer reference in cipso_v4_doi_free
From: Sasha Levin <sashal@kernel.org>
Date: 2021-09-09 13:26:11
Also in:
linux-security-module, lkml, netdev
Subsystem:
networking [general], networking [labeled] (netlabel, labeled ipsec, secmark), the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Paul Moore, Linus Torvalds
From: 王贇 <redacted> [ Upstream commit 733c99ee8be9a1410287cdbb943887365e83b2d6 ] In netlbl_cipsov4_add_std() when 'doi_def->map.std' alloc failed, we sometime observe panic: BUG: kernel NULL pointer dereference, address: ... RIP: 0010:cipso_v4_doi_free+0x3a/0x80 ... Call Trace: netlbl_cipsov4_add_std+0xf4/0x8c0 netlbl_cipsov4_add+0x13f/0x1b0 genl_family_rcv_msg_doit.isra.15+0x132/0x170 genl_rcv_msg+0x125/0x240 This is because in cipso_v4_doi_free() there is no check on 'doi_def->map.std' when 'doi_def->type' equal 1, which is possibe, since netlbl_cipsov4_add_std() haven't initialize it before alloc 'doi_def->map.std'. This patch just add the check to prevent panic happen for similar cases. Reported-by: Abaci <redacted> Signed-off-by: Michael Wang <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- net/netlabel/netlabel_cipso_v4.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/netlabel/netlabel_cipso_v4.c b/net/netlabel/netlabel_cipso_v4.c
index 7fd1104ba900..d17a8f3d3387 100644
--- a/net/netlabel/netlabel_cipso_v4.c
+++ b/net/netlabel/netlabel_cipso_v4.c@@ -163,8 +163,8 @@ static int netlbl_cipsov4_add_std(struct genl_info *info, return -ENOMEM; doi_def->map.std = kzalloc(sizeof(*doi_def->map.std), GFP_KERNEL); if (doi_def->map.std == NULL) { - ret_val = -ENOMEM; - goto add_std_failure; + kfree(doi_def); + return -ENOMEM; } doi_def->type = CIPSO_V4_MAP_TRANS;
--
2.30.2