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author王贇 <yun.wang@linux.alibaba.com>2021-08-26 11:42:42 +0800
committerDavid S. Miller <davem@davemloft.net>2021-08-26 12:20:47 +0100
commit733c99ee8be9a1410287cdbb943887365e83b2d6 (patch)
treed70788577b4e957040713a11dc5442d6e981ea58
parent96a6b93b69880b2c978e1b2be9cae6970b605008 (diff)
net: fix NULL pointer reference in cipso_v4_doi_free
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>
-rw-r--r--net/ipv4/cipso_ipv4.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 099259fc826a..7fbd0b532f52 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -465,14 +465,16 @@ 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);
}