From fb89c39455e4b49881c5a42761bd71f03d3ef888 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Thu, 15 Aug 2019 23:56:35 +0300 Subject: xdp: unpin xdp umem pages in error path Fix mem leak caused by missed unpin routine for umem pages. Fixes: 8aef7340ae9695 ("xsk: introduce xdp_umem_page") Signed-off-by: Ivan Khoronzhuk Acked-by: Jonathan Lemon Signed-off-by: Daniel Borkmann --- net/xdp/xdp_umem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 83de74ca729a..688aac7a6943 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -365,7 +365,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) umem->pages = kcalloc(umem->npgs, sizeof(*umem->pages), GFP_KERNEL); if (!umem->pages) { err = -ENOMEM; - goto out_account; + goto out_pin; } for (i = 0; i < umem->npgs; i++) @@ -373,6 +373,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) return 0; +out_pin: + xdp_umem_unpin_pages(umem); out_account: xdp_umem_unaccount_pages(umem); return err; -- cgit v1.2.3 From db38de39684dda2bf307f41797db2831deba64e9 Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Wed, 21 Aug 2019 14:17:20 +0200 Subject: flow_dissector: Fix potential use-after-free on BPF_PROG_DETACH Call to bpf_prog_put(), with help of call_rcu(), queues an RCU-callback to free the program once a grace period has elapsed. The callback can run together with new RCU readers that started after the last grace period. New RCU readers can potentially see the "old" to-be-freed or already-freed pointer to the program object before the RCU update-side NULLs it. Reorder the operations so that the RCU update-side resets the protected pointer before the end of the grace period after which the program will be freed. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Reported-by: Lorenz Bauer Signed-off-by: Jakub Sitnicki Acked-by: Petar Penkov Signed-off-by: Daniel Borkmann --- net/core/flow_dissector.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 3e6fedb57bc1..2470b4b404e6 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -142,8 +142,8 @@ int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr) mutex_unlock(&flow_dissector_mutex); return -ENOENT; } - bpf_prog_put(attached); RCU_INIT_POINTER(net->flow_dissector_prog, NULL); + bpf_prog_put(attached); mutex_unlock(&flow_dissector_mutex); return 0; } -- cgit v1.2.3 From 2c238177bd7f4b14bdf7447cc1cd9bb791f147e6 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Tue, 20 Aug 2019 17:50:25 +0200 Subject: bpf: allow narrow loads of some sk_reuseport_md fields with offset > 0 test_select_reuseport fails on s390 due to verifier rejecting test_select_reuseport_kern.o with the following message: ; data_check.eth_protocol = reuse_md->eth_protocol; 18: (69) r1 = *(u16 *)(r6 +22) invalid bpf_context access off=22 size=2 This is because on big-endian machines casts from __u32 to __u16 are generated by referencing the respective variable as __u16 with an offset of 2 (as opposed to 0 on little-endian machines). The verifier already has all the infrastructure in place to allow such accesses, it's just that they are not explicitly enabled for eth_protocol field. Enable them for eth_protocol field by using bpf_ctx_range instead of offsetof. Ditto for ip_protocol, bind_inany and len, since they already allow narrowing, and the same problem can arise when working with them. Fixes: 2dbb9b9e6df6 ("bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT") Signed-off-by: Ilya Leoshkevich Signed-off-by: Daniel Borkmann --- net/core/filter.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index 7878f918b8c0..4c6a252d4212 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -8757,13 +8757,13 @@ sk_reuseport_is_valid_access(int off, int size, return size == size_default; /* Fields that allow narrowing */ - case offsetof(struct sk_reuseport_md, eth_protocol): + case bpf_ctx_range(struct sk_reuseport_md, eth_protocol): if (size < FIELD_SIZEOF(struct sk_buff, protocol)) return false; /* fall through */ - case offsetof(struct sk_reuseport_md, ip_protocol): - case offsetof(struct sk_reuseport_md, bind_inany): - case offsetof(struct sk_reuseport_md, len): + case bpf_ctx_range(struct sk_reuseport_md, ip_protocol): + case bpf_ctx_range(struct sk_reuseport_md, bind_inany): + case bpf_ctx_range(struct sk_reuseport_md, len): bpf_ctx_record_field_size(info, size_default); return bpf_ctx_narrow_access_ok(off, size, size_default); -- cgit v1.2.3