On Mon, Aug 30, 2021 at 8:01 PM Sasha Levin sashal@kernel.org wrote:
From: 王贇 yun.wang@linux.alibaba.com
[ Upstream commit 733c99ee8be9a1410287cdbb943887365e83b2d6 ]
Hi Sasha,
Michael Wang has sent a v2 patch [1] for this bug and it is merged into netdev/net-next.git. However, the v1 patch is already in the upstream tree.
How do you guys handle such a issue?
[1] https://lkml.org/lkml/2021/8/30/229
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 abaci@linux.alibaba.com Signed-off-by: Michael Wang yun.wang@linux.alibaba.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org
net/ipv4/cipso_ipv4.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index e0480c6cebaa..16bbd62db791 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -466,14 +466,16 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) if (!doi_def) return;
switch (doi_def->type) {case CIPSO_V4_MAP_TRANS:kfree(doi_def->map.std->lvl.cipso);kfree(doi_def->map.std->lvl.local);kfree(doi_def->map.std->cat.cipso);kfree(doi_def->map.std->cat.local);kfree(doi_def->map.std);break;
if (doi_def->map.std) {switch (doi_def->type) {case CIPSO_V4_MAP_TRANS:kfree(doi_def->map.std->lvl.cipso);kfree(doi_def->map.std->lvl.local);kfree(doi_def->map.std->cat.cipso);kfree(doi_def->map.std->cat.local);kfree(doi_def->map.std);break;} } kfree(doi_def);}
2.30.2