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2018-01-26bpf: fix subprog verifier bypass by div/mod by 0 exceptionDaniel Borkmann1-1/+8
One of the ugly leftovers from the early eBPF days is that div/mod operations based on registers have a hard-coded src_reg == 0 test in the interpreter as well as in JIT code generators that would return from the BPF program with exit code 0. This was basically adopted from cBPF interpreter for historical reasons. There are multiple reasons why this is very suboptimal and prone to bugs. To name one: the return code mapping for such abnormal program exit of 0 does not always match with a suitable program type's exit code mapping. For example, '0' in tc means action 'ok' where the packet gets passed further up the stack, which is just undesirable for such cases (e.g. when implementing policy) and also does not match with other program types. While trying to work out an exception handling scheme, I also noticed that programs crafted like the following will currently pass the verifier: 0: (bf) r6 = r1 1: (85) call pc+8 caller: R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 callee: frame1: R1=ctx(id=0,off=0,imm=0) R10=fp0,call_1 10: (b4) (u32) r2 = (u32) 0 11: (b4) (u32) r3 = (u32) 1 12: (3c) (u32) r3 /= (u32) r2 13: (61) r0 = *(u32 *)(r1 +76) 14: (95) exit returning from callee: frame1: R0_w=pkt(id=0,off=0,r=0,imm=0) R1=ctx(id=0,off=0,imm=0) R2_w=inv0 R3_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0,call_1 to caller at 2: R0_w=pkt(id=0,off=0,r=0,imm=0) R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 from 14 to 2: R0=pkt(id=0,off=0,r=0,imm=0) R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 2: (bf) r1 = r6 3: (61) r1 = *(u32 *)(r1 +80) 4: (bf) r2 = r0 5: (07) r2 += 8 6: (2d) if r2 > r1 goto pc+1 R0=pkt(id=0,off=0,r=8,imm=0) R1=pkt_end(id=0,off=0,imm=0) R2=pkt(id=0,off=8,r=8,imm=0) R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 7: (71) r0 = *(u8 *)(r0 +0) 8: (b7) r0 = 1 9: (95) exit from 6 to 8: safe processed 16 insns (limit 131072), stack depth 0+0 Basically what happens is that in the subprog we make use of a div/mod by 0 exception and in the 'normal' subprog's exit path we just return skb->data back to the main prog. This has the implication that the verifier thinks we always get a pkt pointer in R0 while we still have the implicit 'return 0' from the div as an alternative unconditional return path earlier. Thus, R0 then contains 0, meaning back in the parent prog we get the address range of [0x0, skb->data_end] as read and writeable. Similar can be crafted with other pointer register types. Since i) BPF_ABS/IND is not allowed in programs that contain BPF to BPF calls (and generally it's also disadvised to use in native eBPF context), ii) unknown opcodes don't return zero anymore, iii) we don't return an exception code in dead branches, the only last missing case affected and to fix is the div/mod handling. What we would really need is some infrastructure to propagate exceptions all the way to the original prog unwinding the current stack and returning that code to the caller of the BPF program. In user space such exception handling for similar runtimes is typically implemented with setjmp(3) and longjmp(3) as one possibility which is not available in the kernel, though (kgdb used to implement it in kernel long time ago). I implemented a PoC exception handling mechanism into the BPF interpreter with porting setjmp()/longjmp() into x86_64 and adding a new internal BPF_ABRT opcode that can use a program specific exception code for all exception cases we have (e.g. div/mod by 0, unknown opcodes, etc). While this seems to work in the constrained BPF environment (meaning, here, we don't need to deal with state e.g. from memory allocations that we would need to undo before going into exception state), it still has various drawbacks: i) we would need to implement the setjmp()/longjmp() for every arch supported in the kernel and for x86_64, arm64, sparc64 JITs currently supporting calls, ii) it has unconditional additional cost on main program entry to store CPU register state in initial setjmp() call, and we would need some way to pass the jmp_buf down into ___bpf_prog_run() for main prog and all subprogs, but also storing on stack is not really nice (other option would be per-cpu storage for this, but it also has the drawback that we need to disable preemption for every BPF program types). All in all this approach would add a lot of complexity. Another poor-man's solution would be to have some sort of additional shared register or scratch buffer to hold state for exceptions, and test that after every call return to chain returns and pass R0 all the way down to BPF prog caller. This is also problematic in various ways: i) an additional register doesn't map well into JITs, and some other scratch space could only be on per-cpu storage, which, again has the side-effect that this only works when we disable preemption, or somewhere in the input context which is not available everywhere either, and ii) this adds significant runtime overhead by putting conditionals after each and every call, as well as implementation complexity. Yet another option is to teach verifier that div/mod can return an integer, which however is also complex to implement as verifier would need to walk such fake 'mov r0,<code>; exit;' sequeuence and there would still be no guarantee for having propagation of this further down to the BPF caller as proper exception code. For parent prog, it is also is not distinguishable from a normal return of a constant scalar value. The approach taken here is a completely different one with little complexity and no additional overhead involved in that we make use of the fact that a div/mod by 0 is undefined behavior. Instead of bailing out, we adapt the same behavior as on some major archs like ARMv8 [0] into eBPF as well: X div 0 results in 0, and X mod 0 results in X. aarch64 and aarch32 ISA do not generate any traps or otherwise aborts of program execution for unsigned divides. I verified this also with a test program compiled by gcc and clang, and the behavior matches with the spec. Going forward we adapt the eBPF verifier to emit such rewrites once div/mod by register was seen. cBPF is not touched and will keep existing 'return 0' semantics. Given the options, it seems the most suitable from all of them, also since major archs have similar schemes in place. Given this is all in the realm of undefined behavior, we still have the option to adapt if deemed necessary and this way we would also have the option of more flexibility from LLVM code generation side (which is then fully visible to verifier). Thus, this patch i) fixes the panic seen in above program and ii) doesn't bypass the verifier observations. [0] ARM Architecture Reference Manual, ARMv8 [ARM DDI 0487B.b] http://infocenter.arm.com/help/topic/com.arm.doc.ddi0487b.b/DDI0487B_b_armv8_arm.pdf 1) aarch64 instruction set: section C3.4.7 and C6.2.279 (UDIV) "A division by zero results in a zero being written to the destination register, without any indication that the division by zero occurred." 2) aarch32 instruction set: section F1.4.8 and F5.1.263 (UDIV) "For the SDIV and UDIV instructions, division by zero always returns a zero result." Fixes: f4d7e40a5b71 ("bpf: introduce function calls (verification)") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-26bpf: xor of a/x in cbpf can be done in 32 bit aluDaniel Borkmann1-2/+2
Very minor optimization; saves 1 byte per program in x86_64 JIT in cBPF prologue. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Add sock_ops R/W access to tclassLawrence Brakmo1-2/+45
Adds direct write access to sk_txhash and access to tclass for ipv6 flows through getsockopt and setsockopt. Sample usage for tclass: bpf_getsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v, sizeof(v)) where skops is a pointer to the ctx (struct bpf_sock_ops). Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Add support for reading sk_state and moreLawrence Brakmo1-11/+132
Add support for reading many more tcp_sock fields state, same as sk->sk_state rtt_min same as sk->rtt_min.s[0].v (current rtt_min) snd_ssthresh rcv_nxt snd_nxt snd_una mss_cache ecn_flags rate_delivered rate_interval_us packets_out retrans_out total_retrans segs_in data_segs_in segs_out data_segs_out lost_out sacked_out sk_txhash bytes_received (__u64) bytes_acked (__u64) Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Adds field bpf_sock_ops_cb_flags to tcp_sockLawrence Brakmo1-0/+34
Adds field bpf_sock_ops_cb_flags to tcp_sock and bpf_sock_ops. Its primary use is to determine if there should be calls to sock_ops bpf program at various points in the TCP code. The field is initialized to zero, disabling the calls. A sock_ops BPF program can set it, per connection and as necessary, when the connection is established. It also adds support for reading and writting the field within a sock_ops BPF program. Reading is done by accessing the field directly. However, writing is done through the helper function bpf_sock_ops_cb_flags_set, in order to return an error if a BPF program is trying to set a callback that is not supported in the current kernel (i.e. running an older kernel). The helper function returns 0 if it was able to set all of the bits set in the argument, a positive number containing the bits that could not be set, or -EINVAL if the socket is not a full TCP socket. Examples of where one could call the bpf program: 1) When RTO fires 2) When a packet is retransmitted 3) When the connection terminates 4) When a packet is sent 5) When a packet is received Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Add write access to tcp_sock and sock fieldsLawrence Brakmo1-0/+48
This patch adds a macro, SOCK_OPS_SET_FIELD, for writing to struct tcp_sock or struct sock fields. This required adding a new field "temp" to struct bpf_sock_ops_kern for temporary storage that is used by sock_ops_convert_ctx_access. It is used to store and recover the contents of a register, so the register can be used to store the address of the sk. Since we cannot overwrite the dst_reg because it contains the pointer to ctx, nor the src_reg since it contains the value we want to store, we need an extra register to contain the address of the sk. Also adds the macro SOCK_OPS_GET_OR_SET_FIELD that calls one of the GET or SET macros depending on the value of the TYPE field. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Make SOCK_OPS_GET_TCP struct independentLawrence Brakmo1-10/+10
Changed SOCK_OPS_GET_TCP to SOCK_OPS_GET_FIELD and added 2 arguments so now it can also work with struct sock fields. The first argument is the name of the field in the bpf_sock_ops struct, the 2nd argument is the name of the field in the OBJ struct. Previous: SOCK_OPS_GET_TCP(FIELD_NAME) New: SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) Where OBJ is either "struct tcp_sock" or "struct sock" (without quotation). BPF_FIELD is the name of the field in the bpf_sock_ops struct and OBJ_FIELD is the name of the field in the OBJ struct. Although the field names are currently the same, the kernel struct names could change in the future and this change makes it easier to support that. Note that adding access to tcp_sock fields in sock_ops programs does not preclude the tcp_sock fields from being removed as long as we are willing to do one of the following: 1) Return a fixed value (e.x. 0 or 0xffffffff), or 2) Make the verifier fail if that field is accessed (i.e. program fails to load) so the user will know that field is no longer supported. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Make SOCK_OPS_GET_TCP size independentLawrence Brakmo1-5/+8
Make SOCK_OPS_GET_TCP helper macro size independent (before only worked with 4-byte fields. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Only reply field should be writeableLawrence Brakmo1-2/+1
Currently, a sock_ops BPF program can write the op field and all the reply fields (reply and replylong). This is a bug. The op field should not have been writeable and there is currently no way to use replylong field for indices >= 1. This patch enforces that only the reply field (which equals replylong[0]) is writeable. Fixes: 40304b2a1567 ("bpf: BPF support for sock_ops") Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25net: Move net:netns_ids destruction out of rtnl_lock() and document locking schemeKirill Tkhai1-18/+44
Currently, we unhash a dying net from netns_ids lists under rtnl_lock(). It's a leftover from the time when net::netns_ids was introduced. There was no net::nsid_lock, and rtnl_lock() was mostly need to order modification of alive nets nsid idr, i.e. for: for_each_net(tmp) { ... id = __peernet2id(tmp, net); idr_remove(&tmp->netns_ids, id); ... } Since we have net::nsid_lock, the modifications are protected by this local lock, and now we may introduce better scheme of netns_ids destruction. Let's look at the functions peernet2id_alloc() and get_net_ns_by_id(). Previous commits taught these functions to work well with dying net acquired from rtnl unlocked lists. And they are the only functions which can hash a net to netns_ids or obtain from there. And as easy to check, other netns_ids operating functions works with id, not with net pointers. So, we do not need rtnl_lock to synchronize cleanup_net() with all them. The another property, which is used in the patch, is that net is unhashed from net_namespace_list in the only place and by the only process. So, we avoid excess rcu_read_lock() or rtnl_lock(), when we'are iterating over the list in unhash_nsid(). All the above makes possible to keep rtnl_lock() locked only for net->list deletion, and completely avoid it for netns_ids unhashing and destruction. As these two doings may take long time (e.g., memory allocation to send skb), the patch should positively act on the scalability and signify decrease the time, which rtnl_lock() is held in cleanup_net(). Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24dev_ioctl(): move copyin/copyout to callersAl Viro1-61/+24
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-24lift handling of SIOCIW... out of dev_ioctl()Al Viro1-18/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-24net: separate SIOCGIFCONF handling from dev_ioctl()Al Viro1-22/+7
Only two of dev_ioctl() callers may pass SIOCGIFCONF to it. Separating that codepath from the rest of dev_ioctl() allows both to simplify dev_ioctl() itself (all other cases work with struct ifreq *) *and* seriously simplify the compat side of that beast: all it takes is passing to inet_gifconf() an extra argument - the size of individual records (sizeof(struct ifreq) or sizeof(struct compat_ifreq)). With dev_ifconf() called directly from sock_do_ioctl()/compat_dev_ifconf() that's easy to arrange. As the result, compat side of SIOCGIFCONF doesn't need any allocations, copy_in_user() back and forth, etc. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-24pktgen: Clean read user supplied flag messDmitry Safonov1-105/+39
Don't use error-prone-brute-force way. Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24pktgen: Remove brute-force printing of flagsDmitry Safonov1-58/+19
Add macro generated pkt_flag_names array, with a little help of which the flags can be printed by using an index. Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24pktgen: Add behaviour flags macro to generate flags/namesDmitry Safonov1-23/+34
PKT_FALGS macro will be used to add package behavior names definitions to simplify the code that prints/reads pkg flags. Sorted the array in order of printing the flags in pktgen_if_show() Note: Renamed IPSEC_ON => IPSEC for simplicity. No visible behavior change expected. Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24pktgen: Add missing !flag parametersDmitry Safonov1-1/+7
o FLOW_SEQ now can be disabled with pgset "flag !FLOW_SEQ" o FLOW_SEQ and FLOW_RND are antonyms, as it's shown by pktgen_if_show() o IPSEC now may be disabled Note, that IPV6 is enabled with dst6/src6 parameters, not with a flag parameter. Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-23net: link_watch: mark bonding link events urgentRoopa Prabhu1-1/+1
It takes 1sec for bond link down notification to hit user-space when all slaves of the bond go down. 1sec is too long for protocol daemons in user-space relying on bond notification to recover (eg: multichassis lag implementations in user-space). Since the link event code already marks team device port link events as urgent, this patch moves the code to cover all lag ports and master. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-4/+15
en_rx_am.c was deleted in 'net-next' but had a bug fixed in it in 'net'. The esp{4,6}_offload.c conflicts were overlapping changes. The 'out' label is removed so we just return ERR_PTR(-EINVAL) directly. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-23net: core: Fix kernel-doc for netdev_upper_link()Florian Fainelli1-0/+2
Fixes the following warnings: ./net/core/dev.c:6438: warning: No description found for parameter 'extack' ./net/core/dev.c:6461: warning: No description found for parameter 'extack' Fixes: 42ab19ee9029 ("net: Add extack to upper device linking") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-23net: core: Fix kernel-doc for call_netdevice_notifiers_info()Florian Fainelli1-1/+0
Remove the @dev comment, since we do not have a net_device argument, fixes the following kernel doc warning: /net/core/dev.c:1707: warning: Excess function parameter 'dev' description in 'call_netdevice_notifiers_info' Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-22net: qdisc_pkt_len_init() should be more robustEric Dumazet1-4/+15
Without proper validation of DODGY packets, we might very well feed qdisc_pkt_len_init() with invalid GSO packets. tcp_hdrlen() might access out-of-bound data, so let's use skb_header_pointer() and proper checks. Whole story is described in commit d0c081b49137 ("flow_dissector: properly cap thoff field") We have the goal of validating DODGY packets earlier in the stack, so we might very well revert this fix in the future. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Jason Wang <jasowang@redhat.com> Reported-by: syzbot+9da69ebac7dddd804552@syzkaller.appspotmail.com Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-22net: core: Expose number of link up/down transitionsDavid Decotigny2-3/+35
Expose the number of times the link has been going UP or DOWN, and update the "carrier_changes" counter to be the sum of these two events. While at it, also update the sysfs-class-net documentation to cover: carrier_changes (3.15), carrier_up_count (4.16) and carrier_down_count (4.16) Signed-off-by: David Decotigny <decot@googlers.com> [Florian: * rebase * add documentation * merge carrier_changes with up/down counters] Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-22devlink: fix memory leak on 'resource'Colin Ian King1-0/+1
Currently, if the call to devlink_resource_find returns null then the error exit path does not free the devlink_resource 'resource' and a memory leak occurs. Fix this by kfree'ing resource on the error exit path. Detected by CoverityScan, CID#1464184 ("Resource leak") Fixes: d9f9b9a4d05f ("devlink: Add support for resource abstraction") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2-9/+58
Alexei Starovoitov says: ==================== pull-request: bpf-next 2018-01-19 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) bpf array map HW offload, from Jakub. 2) support for bpf_get_next_key() for LPM map, from Yonghong. 3) test_verifier now runs loaded programs, from Alexei. 4) xdp cpumap monitoring, from Jesper. 5) variety of tests, cleanups and small x64 JIT optimization, from Daniel. 6) user space can now retrieve HW JITed program, from Jiong. Note there is a minor conflict between Russell's arm32 JIT fixes and removal of bpf_jit_enable variable by Daniel which should be resolved by keeping Russell's comment and removing that variable. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-2/+5
The BPF verifier conflict was some minor contextual issue. The TUN conflict was less trivial. Cong Wang fixed a memory leak of tfile->tx_array in 'net'. This is an skb_array. But meanwhile in net-next tun changed tfile->tx_arry into tfile->tx_ring which is a ptr_ring. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19bpf: move event_output to const_size_or_zero for xdp/skb as wellDaniel Borkmann1-2/+2
Similar rationale as in a60dd35d2e39 ("bpf: change bpf_perf_event_output arg5 type to ARG_CONST_SIZE_OR_ZERO"), change the type to CONST_SIZE_OR_ZERO such that we can better deal with optimized code. No changes needed in bpf_event_output() as it can also deal with 0 size entirely (e.g. as only wake-up signal with empty frame in perf RB, or packet dumps w/o meta data as another such possibility). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-19bpf: restrict access to core bpf sysctlsDaniel Borkmann1-3/+43
Given BPF reaches far beyond just networking these days, it was never intended to allow setting and in some cases reading those knobs out of a user namespace root running without CAP_SYS_ADMIN, thus tighten such access. Also the bpf_jit_enable = 2 debugging mode should only be allowed if kptr_restrict is not set since it otherwise can leak addresses to the kernel log. Dump a note to the kernel log that this is for debugging JITs only when enabled. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-19bpf: get rid of pure_initcall dependency to enable jitsDaniel Borkmann1-6/+12
Having a pure_initcall() callback just to permanently enable BPF JITs under CONFIG_BPF_JIT_ALWAYS_ON is unnecessary and could leave a small race window in future where JIT is still disabled on boot. Since we know about the setting at compilation time anyway, just initialize it properly there. Also consolidate all the individual bpf_jit_enable variables into a single one and move them under one location. Moreover, don't allow for setting unspecified garbage values on them. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-19bpf: add csum_diff helper to xdp as wellDaniel Borkmann1-0/+2
Useful for porting cls_bpf programs w/o increasing program complexity limits much at the same time, so add the helper to XDP as well. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-19devlink: Make some functions staticWei Yongjun1-2/+3
Fixes the following sparse warnings: net/core/devlink.c:2297:25: warning: symbol 'devlink_resource_find' was not declared. Should it be static? net/core/devlink.c:2322:6: warning: symbol 'devlink_resource_validate_children' was not declared. Should it be static? Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-18bpf: allow socket_filter programs to use bpf_prog_test_runAlexei Starovoitov1-0/+1
in order to improve test coverage allow socket_filter program type to be run via bpf_prog_test_run command. Since such programs can be loaded by non-root tighten permissions for bpf_prog_test_run to be root only to avoid surprises. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-18flow_dissector: properly cap thoff fieldEric Dumazet1-2/+1
syzbot reported yet another crash [1] that is caused by insufficient validation of DODGY packets. Two bugs are happening here to trigger the crash. 1) Flow dissection leaves with incorrect thoff field. 2) skb_probe_transport_header() sets transport header to this invalid thoff, even if pointing after skb valid data. 3) qdisc_pkt_len_init() reads out-of-bound data because it trusts tcp_hdrlen(skb) Possible fixes : - Full flow dissector validation before injecting bad DODGY packets in the stack. This approach was attempted here : https://patchwork.ozlabs.org/patch/ 861874/ - Have more robust functions in the core. This might be needed anyway for stable versions. This patch fixes the flow dissection issue. [1] CPU: 1 PID: 3144 Comm: syzkaller271204 Not tainted 4.15.0-rc4-mm1+ #49 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:355 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:413 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:432 __tcp_hdrlen include/linux/tcp.h:35 [inline] tcp_hdrlen include/linux/tcp.h:40 [inline] qdisc_pkt_len_init net/core/dev.c:3160 [inline] __dev_queue_xmit+0x20d3/0x2200 net/core/dev.c:3465 dev_queue_xmit+0x17/0x20 net/core/dev.c:3554 packet_snd net/packet/af_packet.c:2943 [inline] packet_sendmsg+0x3ad5/0x60a0 net/packet/af_packet.c:2968 sock_sendmsg_nosec net/socket.c:628 [inline] sock_sendmsg+0xca/0x110 net/socket.c:638 sock_write_iter+0x31a/0x5d0 net/socket.c:907 call_write_iter include/linux/fs.h:1776 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x1f/0x96 Fixes: 34fad54c2537 ("net: __skb_flow_dissect() must cap its return value") Fixes: a6e544b0a88b ("flow_dissector: Jump to exit code in __skb_flow_dissect") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller1-0/+4
Daniel Borkmann says: ==================== pull-request: bpf 2018-01-18 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix a divide by zero due to wrong if (src_reg == 0) check in 64-bit mode. Properly handle this in interpreter and mask it also generically in verifier to guard against similar checks in JITs, from Eric and Alexei. 2) Fix a bug in arm64 JIT when tail calls are involved and progs have different stack sizes, from Daniel. 3) Reject stores into BPF context that are not expected BPF_STX | BPF_MEM variant, from Daniel. 4) Mark dst reg as unknown on {s,u}bounds adjustments when the src reg has derived bounds from dead branches, from Daniel. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17net: Remove spinlock from get_net_ns_by_id()Kirill Tkhai1-2/+0
idr_find() is safe under rcu_read_lock() and maybe_get_net() guarantees that net is alive. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17net: Fix possible race in peernet2id_alloc()Kirill Tkhai1-2/+11
peernet2id_alloc() is racy without rtnl_lock() as refcount_read(&peer->count) under net->nsid_lock does not guarantee, peer is alive: rcu_read_lock() peernet2id_alloc() .. spin_lock_bh(&net->nsid_lock) .. refcount_read(&peer->count) (!= 0) .. .. put_net() .. cleanup_net() .. for_each_net(tmp) .. spin_lock_bh(&tmp->nsid_lock) .. __peernet2id(tmp, net) == -1 .. .. .. .. __peernet2id_alloc(alloc == true) .. .. .. rcu_read_unlock() .. .. synchronize_rcu() .. kmem_cache_free(net) After the above situation, net::netns_id contains id pointing to freed memory, and any other dereferencing by the id will operate with this freed memory. Currently, peernet2id_alloc() is used under rtnl_lock() everywhere except ovs_vport_cmd_fill_info(), and this race can't occur. But peernet2id_alloc() is generic interface, and better we fix it before someone really starts use it in wrong context. v2: Don't place refcount_read(&net->count) under net->nsid_lock as suggested by Eric W. Biederman <ebiederm@xmission.com> v3: Rebase on top of net-next Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+2
Overlapping changes all over. The mini-qdisc bits were a little bit tricky, however. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-4/+3
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-01-17 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add initial BPF map offloading for nfp driver. Currently only programs were supported so far w/o being able to access maps. Offloaded programs are right now only allowed to perform map lookups, and control path is responsible for populating the maps. BPF core infrastructure along with nfp implementation is provided, from Jakub. 2) Various follow-ups to Josef's BPF error injections. More specifically that includes: properly check whether the error injectable event is on function entry or not, remove the percpu bpf_kprobe_override and rather compare instruction pointer with original one, separate error-injection from kprobes since it's not limited to it, add injectable error types in order to specify what is the expected type of failure, and last but not least also support the kernel's fault injection framework, all from Masami. 3) Various misc improvements and cleanups to the libbpf Makefile. That is, fix permissions when installing BPF header files, remove unused variables and functions, and also install the libbpf.h header, from Jesper. 4) When offloading to nfp JIT and the BPF insn is unsupported in the JIT, then reject right at verification time. Also fix libbpf with regards to ELF section name matching by properly treating the program type as prefix. Both from Quentin. 5) Add -DPACKAGE to bpftool when including bfd.h for the disassembler. This is needed, for example, when building libfd from source as bpftool doesn't supply a config.h for bfd.h. Fix from Jiong. 6) xdp_convert_ctx_access() is simplified since it doesn't need to set target size during verification, from Jesper. 7) Let bpftool properly recognize BPF_PROG_TYPE_CGROUP_DEVICE program types, from Roman. 8) Various functions in BPF cpumap were not declared static, from Wei. 9) Fix a double semicolon in BPF samples, from Luis. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16net: delete /proc THIS_MODULE referencesAlexey Dobriyan4-9/+0
/proc has been ignoring struct file_operations::owner field for 10 years. Specifically, it started with commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba ("Fix rmmod/read/write races in /proc entries"). Notice the chunk where inode->i_fop is initialized with proxy struct file_operations for regular files: - if (de->proc_fops) - inode->i_fop = de->proc_fops; + if (de->proc_fops) { + if (S_ISREG(inode->i_mode)) + inode->i_fop = &proc_reg_file_ops; + else + inode->i_fop = de->proc_fops; + } VFS stopped pinning module at this point. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16devlink: Add relation between dpipe and resourceArkadi Sharshevsky1-0/+37
The hardware processes which are modeled via dpipe commonly use some internal hardware resources. Such relation can improve the understanding of hardware limitations. The number of resource's unit consumed per table's entry are also provided for each table. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16devlink: Add support for reloadArkadi Sharshevsky1-0/+47
Add support for performing driver hot reload. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16devlink: Add support for resource abstractionArkadi Sharshevsky1-0/+374
Add support for hardware resource abstraction over devlink. Each resource is identified via id, furthermore it contains information regarding its size and its related sub resources. Each resource can also provide its current occupancy. In some cases the sizes of some resources can be changed, yet for those changes to take place a hot driver reload may be needed. The reload capability will be introduced in the next patch. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16devlink: Add per devlink instance lockArkadi Sharshevsky1-59/+77
This is a preparation before introducing resources and hot reload support. Currently there are two global lock where one protects all devlink access, and the second one protects devlink port access. This patch adds per devlink instance lock which protects the internal members which are the sb/dpipe/ resource/ports. By introducing this lock the global devlink port lock can be discarded. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-15net: Restrict unwhitelisted proto caches to size 0Kees Cook1-3/+1
Now that protocols have been annotated (the copy of icsk_ca_ops->name is of an ops field from outside the slab cache): $ git grep 'copy_.*_user.*sk.*->' caif/caif_socket.c: copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { ipv4/raw.c: if (copy_from_user(&raw_sk(sk)->filter, optval, optlen)) ipv4/raw.c: copy_to_user(optval, &raw_sk(sk)->filter, len)) ipv4/tcp.c: if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) ipv4/tcp.c: if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len)) ipv6/raw.c: if (copy_from_user(&raw6_sk(sk)->filter, optval, optlen)) ipv6/raw.c: if (copy_to_user(optval, &raw6_sk(sk)->filter, len)) sctp/socket.c: if (copy_from_user(&sctp_sk(sk)->subscribe, optval, optlen)) sctp/socket.c: if (copy_to_user(optval, &sctp_sk(sk)->subscribe, len)) sctp/socket.c: if (copy_to_user(optval, &sctp_sk(sk)->initmsg, len)) we can switch the default proto usercopy region to size 0. Any protocols needing to add whitelisted regions must annotate the fields with the useroffset and usersize fields of struct proto. This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2018-01-15net: Define usercopy region in struct proto slab cacheDavid Windsor1-1/+5
In support of usercopy hardening, this patch defines a region in the struct proto slab cache in which userspace copy operations are allowed. Some protocols need to copy objects to/from userspace, and they can declare the region via their proto structure with the new usersize and useroffset fields. Initially, if no region is specified (usersize == 0), the entire field is marked as whitelisted. This allows protocols to be whitelisted in subsequent patches. Once all protocols have been annotated, the full-whitelist default can be removed. This region is known as the slab cache's usercopy region. Slab caches can now check that each dynamically sized copy operation involving cache-managed memory falls entirely within the slab's usercopy region. This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor <dave@nullcore.net> [kees: adjust commit log, split off per-proto patches] [kees: add logic for by-default full-whitelist] Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2018-01-15net: Allow neigh contructor functions ability to modify the primary_keyJim Westfall1-2/+2
Use n->primary_key instead of pkey to account for the possibility that a neigh constructor function may have modified the primary_key value. Signed-off-by: Jim Westfall <jwestfall@surrealistic.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-15net: Convert atomic_t net::count to refcount_tKirill Tkhai2-7/+7
Since net could be obtained from RCU lists, and there is a race with net destruction, the patch converts net::count to refcount_t. This provides sanity checks for the cases of incrementing counter of already dead net, when maybe_get_net() has to used instead of get_net(). Drivers: allyesconfig and allmodconfig are OK. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-14bpf: fix 32-bit divide by zeroAlexei Starovoitov1-0/+4
due to some JITs doing if (src_reg == 0) check in 64-bit mode for div/mod operations mask upper 32-bits of src register before doing the check Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Fixes: 7a12b5031c6b ("sparc64: Add eBPF JIT.") Reported-by: syzbot+48340bb518e88849e2e3@syzkaller.appspotmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-13bpf: simplify xdp_convert_ctx_access for xdp_rxq_infoJesper Dangaard Brouer1-4/+3
As pointed out by Daniel Borkmann, using bpf_target_off() is not necessary for xdp_rxq_info when extracting queue_index and ifindex, as these members are u32 like BPF_W. Also fix trivial spelling mistake introduced in same commit. Fixes: 02dd3291b2f0 ("bpf: finally expose xdp_rxq_info to XDP bpf-programs") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-12net: Cap number of queues even with accel_privAlexander Duyck1-2/+1
With the recent fix to ixgbe we can cap the number of queues always regardless of if accel_priv is being used or not since the actual number of queues are being reported via real_num_tx_queues. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Tested-by: Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>