From: 王贇 yun.wang@linux.alibaba.com
[ 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 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 e8b8dd1cb157..7372ba2659df 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -480,14 +480,16 @@ 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); }