[dpdk-dev] [PATCH] ip_frag: fix double free of chained mbufs

[Allain Legacy]

The first mbuf and the last mbuf to be visited in the preceeding loop
are not set to NULL in the fragmentation table.  This creates the
possibility of a double free when the fragmentation table is later freed
with rte_ip_frag_table_destroy().

Fixes: 95908f52393d ("ip_frag: free mbufs on reassembly table destroy")

Signed-off-by: Allain Legacy <allain.leg...@windriver.com>
---
 lib/librte_ip_frag/rte_ipv4_reassembly.c | 4 +++-
 lib/librte_ip_frag/rte_ipv6_reassembly.c | 2 ++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/librte_ip_frag/rte_ipv4_reassembly.c 
b/lib/librte_ip_frag/rte_ipv4_reassembly.c
index 82e831ca3..42974fb8b 100644
--- a/lib/librte_ip_frag/rte_ipv4_reassembly.c
+++ b/lib/librte_ip_frag/rte_ipv4_reassembly.c
@@ -25,7 +25,7 @@ ipv4_frag_reassemble(struct ip_frag_pkt *fp)
        /*start from the last fragment. */
        m = fp->frags[IP_LAST_FRAG_IDX].mb;
        ofs = fp->frags[IP_LAST_FRAG_IDX].ofs;
-       curr_idx = IP_LAST_FRAG_IDX;
+       curr_idx =      IP_LAST_FRAG_IDX;
 
        while (ofs != first_len) {
 
@@ -59,7 +59,9 @@ ipv4_frag_reassemble(struct ip_frag_pkt *fp)
        /* chain with the first fragment. */
        rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
        rte_pktmbuf_chain(fp->frags[IP_FIRST_FRAG_IDX].mb, m);
+       fp->frags[curr_idx].mb = NULL;
        m = fp->frags[IP_FIRST_FRAG_IDX].mb;
+       fp->frags[IP_FIRST_FRAG_IDX].mb = NULL;
 
        /* update mbuf fields for reassembled packet. */
        m->ol_flags |= PKT_TX_IP_CKSUM;
diff --git a/lib/librte_ip_frag/rte_ipv6_reassembly.c 
b/lib/librte_ip_frag/rte_ipv6_reassembly.c
index 3479fabb8..db249fe60 100644
--- a/lib/librte_ip_frag/rte_ipv6_reassembly.c
+++ b/lib/librte_ip_frag/rte_ipv6_reassembly.c
@@ -82,7 +82,9 @@ ipv6_frag_reassemble(struct ip_frag_pkt *fp)
        /* chain with the first fragment. */
        rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
        rte_pktmbuf_chain(fp->frags[IP_FIRST_FRAG_IDX].mb, m);
+       fp->frags[curr_idx].mb = NULL;
        m = fp->frags[IP_FIRST_FRAG_IDX].mb;
+       fp->frags[IP_FIRST_FRAG_IDX].mb = NULL;
 
        /* update mbuf fields for reassembled packet. */
        m->ol_flags |= PKT_TX_IP_CKSUM;
-- 
2.12.1