On Mon, Aug 30, 2021 at 8:01 PM Sasha Levin <sashal@xxxxxxxxxx> wrote: > > From: 王贇 <yun.wang@xxxxxxxxxxxxxxxxx> > > [ 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@xxxxxxxxxxxxxxxxx> > Signed-off-by: Michael Wang <yun.wang@xxxxxxxxxxxxxxxxx> > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > 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 >
