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2016-04-14bpf, samples: add test cases for raw stackDaniel Borkmann1-0/+268
This adds test cases mostly around ARG_PTR_TO_RAW_STACK to check the verifier behaviour. [...] #84 raw_stack: no skb_load_bytes OK #85 raw_stack: skb_load_bytes, no init OK #86 raw_stack: skb_load_bytes, init OK #87 raw_stack: skb_load_bytes, spilled regs around bounds OK #88 raw_stack: skb_load_bytes, spilled regs corruption OK #89 raw_stack: skb_load_bytes, spilled regs corruption 2 OK #90 raw_stack: skb_load_bytes, spilled regs + data OK #91 raw_stack: skb_load_bytes, invalid access 1 OK #92 raw_stack: skb_load_bytes, invalid access 2 OK #93 raw_stack: skb_load_bytes, invalid access 3 OK #94 raw_stack: skb_load_bytes, invalid access 4 OK #95 raw_stack: skb_load_bytes, invalid access 5 OK #96 raw_stack: skb_load_bytes, invalid access 6 OK #97 raw_stack: skb_load_bytes, large access OK Summary: 98 PASSED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08samples/bpf: add map_flags to bpf loaderAlexei Starovoitov1-2/+2
note old loader is compatible with new kernel. map_flags are optional Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-12bpf: add unprivileged bpf testsAlexei Starovoitov1-10/+347
Add new tests samples/bpf/test_verifier: unpriv: return pointer checks that pointer cannot be returned from the eBPF program unpriv: add const to pointer unpriv: add pointer to pointer unpriv: neg pointer checks that pointer arithmetic is disallowed unpriv: cmp pointer with const unpriv: cmp pointer with pointer checks that comparison of pointers is disallowed Only one case allowed 'void *value = bpf_map_lookup_elem(..); if (value == 0) ...' unpriv: check that printk is disallowed since bpf_trace_printk is not available to unprivileged unpriv: pass pointer to helper function checks that pointers cannot be passed to functions that expect integers If function expects a pointer the verifier allows only that type of pointer. Like 1st argument of bpf_map_lookup_elem() must be pointer to map. (applies to non-root as well) unpriv: indirectly pass pointer on stack to helper function checks that pointer stored into stack cannot be used as part of key passed into bpf_map_lookup_elem() unpriv: mangle pointer on stack 1 unpriv: mangle pointer on stack 2 checks that writing into stack slot that already contains a pointer is disallowed unpriv: read pointer from stack in small chunks checks that < 8 byte read from stack slot that contains a pointer is disallowed unpriv: write pointer into ctx checks that storing pointers into skb->fields is disallowed unpriv: write pointer into map elem value checks that storing pointers into element values is disallowed For example: int bpf_prog(struct __sk_buff *skb) { u32 key = 0; u64 *value = bpf_map_lookup_elem(&map, &key); if (value) *value = (u64) skb; } will be rejected. unpriv: partial copy of pointer checks that doing 32-bit register mov from register containing a pointer is disallowed unpriv: pass pointer to tail_call checks that passing pointer as an index into bpf_tail_call is disallowed unpriv: cmp map pointer with zero checks that comparing map pointer with constant is disallowed unpriv: write into frame pointer checks that frame pointer is read-only (applies to root too) unpriv: cmp of frame pointer checks that R10 cannot be using in comparison unpriv: cmp of stack pointer checks that Rx = R10 - imm is ok, but comparing Rx is not unpriv: obfuscate stack pointer checks that Rx = R10 - imm is ok, but Rx -= imm is not Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27ebpf: Allow dereferences of PTR_TO_STACK registersAlex Gartrell1-0/+59
mov %rsp, %r1 ; r1 = rsp add $-8, %r1 ; r1 = rsp - 8 store_q $123, -8(%rsp) ; *(u64*)r1 = 123 <- valid store_q $123, (%r1) ; *(u64*)r1 = 123 <- previously invalid mov $0, %r0 exit ; Always need to exit And we'd get the following error: 0: (bf) r1 = r10 1: (07) r1 += -8 2: (7a) *(u64 *)(r10 -8) = 999 3: (7a) *(u64 *)(r1 +0) = 999 R1 invalid mem access 'fp' Unable to load program We already know that a register is a stack address and the appropriate offset, so we should be able to validate those references as well. Signed-off-by: Alex Gartrell <agartrell@fb.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-07bpf: allow programs to write to certain skb fieldsAlexei Starovoitov1-2/+82
allow programs read/write skb->mark, tc_index fields and ((struct qdisc_skb_cb *)cb)->data. mark and tc_index are generically useful in TC. cb[0]-cb[4] are primarily used to pass arguments from one program to another called via bpf_tail_call() which can be seen in sockex3_kern.c example. All fields of 'struct __sk_buff' are readable to socket and tc_cls_act progs. mark, tc_index are writeable from tc_cls_act only. cb[0]-cb[4] are writeable by both sockets and tc_cls_act. Add verifier tests and improve sample code. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-16bpf: fix two bugs in verification logic when accessing 'ctx' pointerAlexei Starovoitov1-0/+22
1. first bug is a silly mistake. It broke tracing examples and prevented simple bpf programs from loading. In the following code: if (insn->imm == 0 && BPF_SIZE(insn->code) == BPF_W) { } else if (...) { // this part should have been executed when // insn->code == BPF_W and insn->imm != 0 } Obviously it's not doing that. So simple instructions like: r2 = *(u64 *)(r1 + 8) will be rejected. Note the comments in the code around these branches were and still valid and indicate the true intent. Replace it with: if (BPF_SIZE(insn->code) != BPF_W) continue; if (insn->imm == 0) { } else if (...) { // now this code will be executed when // insn->code == BPF_W and insn->imm != 0 } 2. second bug is more subtle. If malicious code is using the same dest register as source register, the checks designed to prevent the same instruction to be used with different pointer types will fail to trigger, since we were assigning src_reg_type when it was already overwritten by check_mem_access(). The fix is trivial. Just move line: src_reg_type = regs[insn->src_reg].type; before check_mem_access(). Add new 'access skb fields bad4' test to check this case. Fixes: 9bac3d6d548e ("bpf: allow extended BPF programs access skb fields") Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-2/+82
Pull networking updates from David Miller: 1) Add BQL support to via-rhine, from Tino Reichardt. 2) Integrate SWITCHDEV layer support into the DSA layer, so DSA drivers can support hw switch offloading. From Floria Fainelli. 3) Allow 'ip address' commands to initiate multicast group join/leave, from Madhu Challa. 4) Many ipv4 FIB lookup optimizations from Alexander Duyck. 5) Support EBPF in cls_bpf classifier and act_bpf action, from Daniel Borkmann. 6) Remove the ugly compat support in ARP for ugly layers like ax25, rose, etc. And use this to clean up the neigh layer, then use it to implement MPLS support. All from Eric Biederman. 7) Support L3 forwarding offloading in switches, from Scott Feldman. 8) Collapse the LOCAL and MAIN ipv4 FIB tables when possible, to speed up route lookups even further. From Alexander Duyck. 9) Many improvements and bug fixes to the rhashtable implementation, from Herbert Xu and Thomas Graf. In particular, in the case where an rhashtable user bulk adds a large number of items into an empty table, we expand the table much more sanely. 10) Don't make the tcp_metrics hash table per-namespace, from Eric Biederman. 11) Extend EBPF to access SKB fields, from Alexei Starovoitov. 12) Split out new connection request sockets so that they can be established in the main hash table. Much less false sharing since hash lookups go direct to the request sockets instead of having to go first to the listener then to the request socks hashed underneath. From Eric Dumazet. 13) Add async I/O support for crytpo AF_ALG sockets, from Tadeusz Struk. 14) Support stable privacy address generation for RFC7217 in IPV6. From Hannes Frederic Sowa. 15) Hash network namespace into IP frag IDs, also from Hannes Frederic Sowa. 16) Convert PTP get/set methods to use 64-bit time, from Richard Cochran. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1816 commits) fm10k: Bump driver version to 0.15.2 fm10k: corrected VF multicast update fm10k: mbx_update_max_size does not drop all oversized messages fm10k: reset head instead of calling update_max_size fm10k: renamed mbx_tx_dropped to mbx_tx_oversized fm10k: update xcast mode before synchronizing multicast addresses fm10k: start service timer on probe fm10k: fix function header comment fm10k: comment next_vf_mbx flow fm10k: don't handle mailbox events in iov_event path and always process mailbox fm10k: use separate workqueue for fm10k driver fm10k: Set PF queues to unlimited bandwidth during virtualization fm10k: expose tx_timeout_count as an ethtool stat fm10k: only increment tx_timeout_count in Tx hang path fm10k: remove extraneous "Reset interface" message fm10k: separate PF only stats so that VF does not display them fm10k: use hw->mac.max_queues for stats fm10k: only show actual queues, not the maximum in hardware fm10k: allow creation of VLAN on default vid fm10k: fix unused warnings ...
2015-04-02samples/bpf: Add simple non-portable kprobe filter exampleAlexei Starovoitov1-1/+1
tracex1_kern.c - C program compiled into BPF. It attaches to kprobe:netif_receive_skb() When skb->dev->name == "lo", it prints sample debug message into trace_pipe via bpf_trace_printk() helper function. tracex1_user.c - corresponding user space component that: - loads BPF program via bpf() syscall - opens kprobes:netif_receive_skb event via perf_event_open() syscall - attaches the program to event via ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); - prints from trace_pipe Note, this BPF program is non-portable. It must be recompiled with current kernel headers. kprobe is not a stable ABI and BPF+kprobe scripts may no longer be meaningful when kernel internals change. No matter in what way the kernel changes, neither the kprobe, nor the BPF program can ever crash or corrupt the kernel, assuming the kprobes, perf and BPF subsystem has no bugs. The verifier will detect that the program is using bpf_trace_printk() and the kernel will print 'this is a DEBUG kernel' warning banner, which means that bpf_trace_printk() should be used for debugging of the BPF program only. Usage: $ sudo tracex1 ping-19826 [000] d.s2 63103.382648: : skb ffff880466b1ca00 len 84 ping-19826 [000] d.s2 63103.382684: : skb ffff880466b1d300 len 84 ping-19826 [000] d.s2 63104.382533: : skb ffff880466b1ca00 len 84 ping-19826 [000] d.s2 63104.382594: : skb ffff880466b1d300 len 84 Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1427312966-8434-7-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17bpf: allow BPF programs access 'protocol' and 'vlan_tci' fieldsAlexei Starovoitov1-0/+9
as a follow on to patch 70006af95515 ("bpf: allow eBPF access skb fields") this patch allows 'protocol' and 'vlan_tci' fields to be accessible from extended BPF programs. The usage of 'protocol', 'vlan_present' and 'vlan_tci' fields is the same as corresponding SKF_AD_PROTOCOL, SKF_AD_VLAN_TAG_PRESENT and SKF_AD_VLAN_TAG accesses in classic BPF. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-15samples: bpf: add skb->field examples and testsAlexei Starovoitov1-0/+70
- modify sockex1 example to count number of bytes in outgoing packets - modify sockex2 example to count number of bytes and packets per flow - add 4 stress tests that exercise 'skb->field' code path of verifier Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-01ebpf: remove kernel test stubsDaniel Borkmann1-2/+3
Now that we have BPF_PROG_TYPE_SOCKET_FILTER up and running, we can remove the test stubs which were added to get the verifier suite up. We can just let the test cases probe under socket filter type instead. In the fill/spill test case, we cannot (yet) access fields from the context (skb), but we may adapt that test case in future. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-18bpf: remove test map scaffolding and user proper typesAlexei Starovoitov1-7/+7
proper types and function helpers are ready. Use them in verifier testsuite. Remove temporary stubs Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-30samples: bpf: add a verifier test and summary lineAlexei Starovoitov1-1/+45
- add a test specifically targeting verifier state pruning. It checks state propagation between registers, storing that state into stack and state pruning algorithm recognizing equivalent stack and register states. - add summary line to spot failures easier Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-21bpf: fix bug in eBPF verifierAlexei Starovoitov1-0/+11
while comparing for verifier state equivalency the comparison was missing a check for uninitialized register. Make sure it does so and add a testcase. Fixes: f1bca824dabb ("bpf: add search pruning optimization to verifier") Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-01bpf: add tests to verifier testsuiteAlexei Starovoitov1-0/+130
add 4 extra tests to cover jump verification better Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26bpf: mini eBPF library, test stubs and verifier testsuiteAlexei Starovoitov1-0/+548
1. the library includes a trivial set of BPF syscall wrappers: int bpf_create_map(int key_size, int value_size, int max_entries); int bpf_update_elem(int fd, void *key, void *value); int bpf_lookup_elem(int fd, void *key, void *value); int bpf_delete_elem(int fd, void *key); int bpf_get_next_key(int fd, void *key, void *next_key); int bpf_prog_load(enum bpf_prog_type prog_type, const struct sock_filter_int *insns, int insn_len, const char *license); bpf_prog_load() stores verifier log into global bpf_log_buf[] array and BPF_*() macros to build instructions 2. test stubs configure eBPF infra with 'unspec' map and program types. These are fake types used by user space testsuite only. 3. verifier tests valid and invalid programs and expects predefined error log messages from kernel. 40 tests so far. $ sudo ./test_verifier #0 add+sub+mul OK #1 unreachable OK #2 unreachable2 OK #3 out of range jump OK #4 out of range jump2 OK #5 test1 ld_imm64 OK ... Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>