From: Xiaolong Huang butterflyhuangxx@gmail.com
mainline inclusion from mainline-5.14 commit 7e78c597c3ebfd0cb329aa09a838734147e4f117 bugzilla: 180972 https://gitee.com/openeuler/kernel/issues/I4DDEL CVE: CVE-2021-3743
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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This check was incomplete, did not consider size is 0:
if (len != ALIGN(size, 4) + hdrlen) goto err;
if size from qrtr_hdr is 0, the result of ALIGN(size, 4) will be 0, In case of len == hdrlen and size == 0 in header this check won't fail and
if (cb->type == QRTR_TYPE_NEW_SERVER) { /* Remote node endpoint can bridge other distant nodes */ const struct qrtr_ctrl_pkt *pkt = data + hdrlen;
qrtr_node_assign(node, le32_to_cpu(pkt->server.node)); }
will also read out of bound from data, which is hdrlen allocated block.
Fixes: 194ccc88297a ("net: qrtr: Support decoding incoming v2 packets") Fixes: ad9d24c9429e ("net: qrtr: fix OOB Read in qrtr_endpoint_post") Signed-off-by: Xiaolong Huang butterflyhuangxx@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Xiu Jianfeng xiujianfeng@huawei.com Reviewed-by: yuehaibing 00384118 yuehaibing@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- net/qrtr/qrtr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c index 6826558483f9..56cffbfa000b 100644 --- a/net/qrtr/qrtr.c +++ b/net/qrtr/qrtr.c @@ -486,7 +486,7 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len) goto err; }
- if (len != ALIGN(size, 4) + hdrlen) + if (!size || len != ALIGN(size, 4) + hdrlen) goto err;
if (cb->dst_port != QRTR_PORT_CTRL && cb->type != QRTR_TYPE_DATA &&