diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-03-12 11:22:49 +0300 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-03-18 15:18:36 +0300 |
| commit | eb0dfc0ef195a04e519b15d73cf25d8c25ee8df7 (patch) | |
| tree | 48152b079fdd9b88da44c66019531b708507b943 /net/ipv6/netfilter | |
| parent | a2fb987c0ecf0498cc17056339cb11d128c46ab7 (diff) | |
| download | linux-eb0dfc0ef195a04e519b15d73cf25d8c25ee8df7.tar.xz | |
inet: frags: change inet_frag_kill() to defer refcount updates
In the following patch, we no longer assume inet_frag_kill()
callers own a reference.
Consuming two refcounts from inet_frag_kill() would lead in UAF.
Propagate the pointer to the refs that will be consumed later
by the final inet_frag_putn() call.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250312082250.1803501-4-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/ipv6/netfilter')
| -rw-r--r-- | net/ipv6/netfilter/nf_conntrack_reasm.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index fcf969f9fe2a..f33acb730dc5 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -123,7 +123,8 @@ static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net) #endif static int nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *skb, - struct sk_buff *prev_tail, struct net_device *dev); + struct sk_buff *prev_tail, struct net_device *dev, + int *refs); static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) { @@ -167,7 +168,8 @@ static struct frag_queue *fq_find(struct net *net, __be32 id, u32 user, static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb, - const struct frag_hdr *fhdr, int nhoff) + const struct frag_hdr *fhdr, int nhoff, + int *refs) { unsigned int payload_len; struct net_device *dev; @@ -221,7 +223,7 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb, * this case. -DaveM */ pr_debug("end of fragment not rounded to 8 bytes.\n"); - inet_frag_kill(&fq->q); + inet_frag_kill(&fq->q, refs); return -EPROTO; } if (end > fq->q.len) { @@ -287,7 +289,7 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb, unsigned long orefdst = skb->_skb_refdst; skb->_skb_refdst = 0UL; - err = nf_ct_frag6_reasm(fq, skb, prev, dev); + err = nf_ct_frag6_reasm(fq, skb, prev, dev, refs); skb->_skb_refdst = orefdst; /* After queue has assumed skb ownership, only 0 or @@ -301,7 +303,7 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb, return -EINPROGRESS; insert_error: - inet_frag_kill(&fq->q); + inet_frag_kill(&fq->q, refs); err: skb_dst_drop(skb); return -EINVAL; @@ -315,13 +317,14 @@ err: * the last and the first frames arrived and all the bits are here. */ static int nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *skb, - struct sk_buff *prev_tail, struct net_device *dev) + struct sk_buff *prev_tail, struct net_device *dev, + int *refs) { void *reasm_data; int payload_len; u8 ecn; - inet_frag_kill(&fq->q); + inet_frag_kill(&fq->q, refs); ecn = ip_frag_ecn_table[fq->ecn]; if (unlikely(ecn == 0xff)) @@ -372,7 +375,7 @@ static int nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *skb, return 0; err: - inet_frag_kill(&fq->q); + inet_frag_kill(&fq->q, refs); return -EINVAL; } @@ -483,7 +486,7 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user) spin_lock_bh(&fq->q.lock); - ret = nf_ct_frag6_queue(fq, skb, fhdr, nhoff); + ret = nf_ct_frag6_queue(fq, skb, fhdr, nhoff, &refs); if (ret == -EPROTO) { skb->transport_header = savethdr; ret = 0; |