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2017-10-14bpf: verifier: set reg_type on context accesses in second passJakub Kicinski
Use a simplified is_valid_access() callback when verifier is used for program analysis by non-host JITs. This allows us to teach the verifier about packet start and packet end offsets for direct packet access. We can extend the callback as needed but for most packet processing needs there isn't much more the offloads may require. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-11bpf: remove redundant variable old_flagsColin Ian King
Variable old_flags is being assigned but is never read; it is redundant and can be removed. Cleans up clang warning: Value stored to 'old_flags' is never read Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10bpf: write back the verifier log buffer as it gets filledJakub Kicinski
Verifier log buffer can be quite large (up to 16MB currently). As Eric Dumazet points out if we allow multiple verification requests to proceed simultaneously, malicious user may use the verifier as a way of allocating large amounts of unswappable memory to OOM the host. Switch to a strategy of allocating a smaller buffer (1024B) and writing it out into the user buffer after every print. While at it remove the old BUG_ON(). This is in preparation of the global verifier lock removal. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10bpf: move instruction printing into a separate fileJakub Kicinski
Separate the instruction printing into a standalone source file. This way sneaky code from tools/ can compile it in directly. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10bpf: move global verifier log into verifier environmentJakub Kicinski
The biggest piece of global state protected by the verifier lock is the verifier_log. Move that log to struct bpf_verifier_env. struct bpf_verifier_env has to be passed now to all invocations of verbose(). Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10bpf: encapsulate verifier log state into a structureJakub Kicinski
Put the loose log_* variables into a structure. This will make it simpler to remove the global verifier state in following patches. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2017-10-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nfDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter/IPVS fixes for net The following patchset contains Netfilter/IPVS fixes for your net tree, they are: 1) Fix packet drops due to incorrect ECN handling in IPVS, from Vadim Fedorenko. 2) Fix splat with mark restoration in xt_socket with non-full-sock, patch from Subash Abhinov Kasiviswanathan. 3) ipset bogusly bails out when adding IPv4 range containing more than 2^31 addresses, from Jozsef Kadlecsik. 4) Incorrect pernet unregistration order in ipset, from Florian Westphal. 5) Races between dump and swap in ipset results in BUG_ON splats, from Ross Lagerwall. 6) Fix chain renames in nf_tables, from JingPiao Chen. 7) Fix race in pernet codepath with ebtables table registration, from Artem Savkov. 8) Memory leak in error path in set name allocation in nf_tables, patch from Arvind Yadav. 9) Don't dump chain counters if they are not available, this fixes a crash when listing the ruleset. 10) Fix out of bound memory read in strlcpy() in x_tables compat code, from Eric Dumazet. 11) Make sure we only process TCP packets in SYNPROXY hooks, patch from Lin Zhang. 12) Cannot load rules incrementally anymore after xt_bpf with pinned objects, added in revision 1. From Shmulik Ladkani. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-09netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'Shmulik Ladkani
Commit 2c16d6033264 ("netfilter: xt_bpf: support ebpf") introduced support for attaching an eBPF object by an fd, with the 'bpf_mt_check_v1' ABI expecting the '.fd' to be specified upon each IPT_SO_SET_REPLACE call. However this breaks subsequent iptables calls: # iptables -A INPUT -m bpf --object-pinned /sys/fs/bpf/xxx -j ACCEPT # iptables -A INPUT -s 5.6.7.8 -j ACCEPT iptables: Invalid argument. Run `dmesg' for more information. That's because iptables works by loading existing rules using IPT_SO_GET_ENTRIES to userspace, then issuing IPT_SO_SET_REPLACE with the replacement set. However, the loaded 'xt_bpf_info_v1' has an arbitrary '.fd' number (from the initial "iptables -m bpf" invocation) - so when 2nd invocation occurs, userspace passes a bogus fd number, which leads to 'bpf_mt_check_v1' to fail. One suggested solution [1] was to hack iptables userspace, to perform a "entries fixup" immediatley after IPT_SO_GET_ENTRIES, by opening a new, process-local fd per every 'xt_bpf_info_v1' entry seen. However, in [2] both Pablo Neira Ayuso and Willem de Bruijn suggested to depricate the xt_bpf_info_v1 ABI dealing with pinned ebpf objects. This fix changes the XT_BPF_MODE_FD_PINNED behavior to ignore the given '.fd' and instead perform an in-kernel lookup for the bpf object given the provided '.path'. It also defines an alias for the XT_BPF_MODE_FD_PINNED mode, named XT_BPF_MODE_PATH_PINNED, to better reflect the fact that the user is expected to provide the path of the pinned object. Existing XT_BPF_MODE_FD_ELF behavior (non-pinned fd mode) is preserved. References: [1] https://marc.info/?l=netfilter-devel&m=150564724607440&w=2 [2] https://marc.info/?l=netfilter-devel&m=150575727129880&w=2 Reported-by: Rafael Buchbinder <rafi@rbk.ms> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-07bpf: Append prog->aux->name in bpf_get_prog_name()Martin KaFai Lau
This patch makes the bpf_prog's name available in kallsyms. The new format is bpf_prog_tag[_name]. Sample kallsyms from running selftests/bpf/test_progs: [root@arch-fb-vm1 ~]# egrep ' bpf_prog_[0-9a-fA-F]{16}' /proc/kallsyms ffffffffa0048000 t bpf_prog_dabf0207d1992486_test_obj_id ffffffffa0038000 t bpf_prog_a04f5eef06a7f555__123456789ABCDE ffffffffa0050000 t bpf_prog_a04f5eef06a7f555 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0Martin KaFai Lau
During get_info_by_fd, the prog/map name is memcpy-ed. It depends on the prog->aux->name and map->name to be zero initialized. bpf_prog_aux is easy to guarantee that aux->name is zero init. The name in bpf_map may be harder to be guaranteed in the future when new map type is added. Hence, this patch makes bpf_obj_name_cpy() to always zero init the prog/map name. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07bpf: fix liveness markingAlexei Starovoitov
while processing Rx = Ry instruction the verifier does regs[insn->dst_reg] = regs[insn->src_reg] which often clears write mark (when Ry doesn't have it) that was just set by check_reg_arg(Rx) prior to the assignment. That causes mark_reg_read() to keep marking Rx in this block as REG_LIVE_READ (since the logic incorrectly misses that it's screened by the write) and in many of its parents (until lucky write into the same Rx or beginning of the program). That causes is_state_visited() logic to miss many pruning opportunities. Furthermore mark_reg_read() logic propagates the read mark for BPF_REG_FP as well (though it's readonly) which causes harmless but unnecssary work during is_state_visited(). Note that do_propagate_liveness() skips FP correctly, so do the same in mark_reg_read() as well. It saves 0.2 seconds for the test below program before after bpf_lb-DLB_L3.o 2604 2304 bpf_lb-DLB_L4.o 11159 3723 bpf_lb-DUNKNOWN.o 1116 1110 bpf_lxc-DDROP_ALL.o 34566 28004 bpf_lxc-DUNKNOWN.o 53267 39026 bpf_netdev.o 17843 16943 bpf_overlay.o 8672 7929 time ~11 sec ~4 sec Fixes: dc503a8ad984 ("bpf/verifier: track liveness for pruning") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Edward Cree <ecree@solarflare.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07bpf: add helper bpf_perf_event_read_value for perf event array mapYonghong Song
Hardware pmu counters are limited resources. When there are more pmu based perf events opened than available counters, kernel will multiplex these events so each event gets certain percentage (but not 100%) of the pmu time. In case that multiplexing happens, the number of samples or counter value will not reflect the case compared to no multiplexing. This makes comparison between different runs difficult. Typically, the number of samples or counter value should be normalized before comparing to other experiments. The typical normalization is done like: normalized_num_samples = num_samples * time_enabled / time_running normalized_counter_value = counter_value * time_enabled / time_running where time_enabled is the time enabled for event and time_running is the time running for event since last normalization. This patch adds helper bpf_perf_event_read_value for kprobed based perf event array map, to read perf counter and enabled/running time. The enabled/running time is accumulated since the perf event open. To achieve scaling factor between two bpf invocations, users can can use cpu_id as the key (which is typical for perf array usage model) to remember the previous value and do the calculation inside the bpf program. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07bpf: perf event change needed for subsequent bpf helpersYonghong Song
This patch does not impact existing functionalities. It contains the changes in perf event area needed for subsequent bpf_perf_event_read_value and bpf_perf_prog_read_value helpers. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Just simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-04bpf: enforce return code for cgroup-bpf programsAlexei Starovoitov
with addition of tnum logic the verifier got smart enough and we can enforce return codes at program load time. For now do so for cgroup-bpf program types. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-04bpf: introduce BPF_PROG_QUERY commandAlexei Starovoitov
introduce BPF_PROG_QUERY command to retrieve a set of either attached programs to given cgroup or a set of effective programs that will execute for events within a cgroup Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-04bpf: multi program support for cgroup+bpfAlexei Starovoitov
introduce BPF_F_ALLOW_MULTI flag that can be used to attach multiple bpf programs to a cgroup. The difference between three possible flags for BPF_PROG_ATTACH command: - NONE(default): No further bpf programs allowed in the subtree. - BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program, the program in this cgroup yields to sub-cgroup program. - BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program, that cgroup program gets run in addition to the program in this cgroup. NONE and BPF_F_ALLOW_OVERRIDE existed before. This patch doesn't change their behavior. It only clarifies the semantics in relation to new flag. Only one program is allowed to be attached to a cgroup with NONE or BPF_F_ALLOW_OVERRIDE flag. Multiple programs are allowed to be attached to a cgroup with BPF_F_ALLOW_MULTI flag. They are executed in FIFO order (those that were attached first, run first) The programs of sub-cgroup are executed first, then programs of this cgroup and then programs of parent cgroup. All eligible programs are executed regardless of return code from earlier programs. To allow efficient execution of multiple programs attached to a cgroup and to avoid penalizing cgroups without any programs attached introduce 'struct bpf_prog_array' which is RCU protected array of pointers to bpf programs. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-03bpf: fix bpf_tail_call() x64 JITAlexei Starovoitov
- bpf prog_array just like all other types of bpf array accepts 32-bit index. Clarify that in the comment. - fix x64 JIT of bpf_tail_call which was incorrectly loading 8 instead of 4 bytes - tighten corresponding check in the interpreter to stay consistent The JIT bug can be triggered after introduction of BPF_F_NUMA_NODE flag in commit 96eabe7a40aa in 4.14. Before that the map_flags would stay zero and though JIT code is wrong it will check bounds correctly. Hence two fixes tags. All other JITs don't have this problem. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Fixes: 96eabe7a40aa ("bpf: Allow selecting numa node during map creation") Fixes: b52f00e6a715 ("x86: bpf_jit: implement bpf_tail_call() helper") Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01bpf: Fix compiler warning on info.map_ids for 32bit platformMartin KaFai Lau
This patch uses u64_to_user_ptr() to cast info.map_ids to a userspace ptr. It also tags the user_map_ids with '__user' for sparse check. Fixes: cb4d2b3f03d8 ("bpf: Add name, load_time, uid and map_ids to bpf_prog_info") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-29bpf: Add map_name to bpf_map_infoMartin KaFai Lau
This patch allows userspace to specify a name for a map during BPF_MAP_CREATE. The map's name can later be exported to user space via BPF_OBJ_GET_INFO_BY_FD. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-29bpf: Add name, load_time, uid and map_ids to bpf_prog_infoMartin KaFai Lau
The patch adds name and load_time to struct bpf_prog_aux. They are also exported to bpf_prog_info. The bpf_prog's name is passed by userspace during BPF_PROG_LOAD. The kernel only stores the first (BPF_PROG_NAME_LEN - 1) bytes and the name stored in the kernel is always \0 terminated. The kernel will reject name that contains characters other than isalnum() and '_'. It will also reject name that is not null terminated. The existing 'user->uid' of the bpf_prog_aux is also exported to the bpf_prog_info as created_by_uid. The existing 'used_maps' of the bpf_prog_aux is exported to the newly added members 'nr_map_ids' and 'map_ids' of the bpf_prog_info. On the input, nr_map_ids tells how big the userspace's map_ids buffer is. On the output, nr_map_ids tells the exact user_map_cnt and it will only copy up to the userspace's map_ids buffer is allowed. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-28bpf/verifier: improve disassembly of BPF_NEG instructionsEdward Cree
BPF_NEG takes only one operand, unlike the bulk of BPF_ALU[64] which are compound-assignments. So give it its own format in print_bpf_insn(). Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-28bpf/verifier: improve disassembly of BPF_END instructionsEdward Cree
print_bpf_insn() was treating all BPF_ALU[64] the same, but BPF_END has a different structure: it has a size in insn->imm (even if it's BPF_X) and uses the BPF_SRC (X or K) to indicate which endianness to use. So it needs different code to print it. Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-26bpf: add meta pointer for direct accessDaniel Borkmann
This work enables generic transfer of metadata from XDP into skb. The basic idea is that we can make use of the fact that the resulting skb must be linear and already comes with a larger headroom for supporting bpf_xdp_adjust_head(), which mangles xdp->data. Here, we base our work on a similar principle and introduce a small helper bpf_xdp_adjust_meta() for adjusting a new pointer called xdp->data_meta. Thus, the packet has a flexible and programmable room for meta data, followed by the actual packet data. struct xdp_buff is therefore laid out that we first point to data_hard_start, then data_meta directly prepended to data followed by data_end marking the end of packet. bpf_xdp_adjust_head() takes into account whether we have meta data already prepended and if so, memmove()s this along with the given offset provided there's enough room. xdp->data_meta is optional and programs are not required to use it. The rationale is that when we process the packet in XDP (e.g. as DoS filter), we can push further meta data along with it for the XDP_PASS case, and give the guarantee that a clsact ingress BPF program on the same device can pick this up for further post-processing. Since we work with skb there, we can also set skb->mark, skb->priority or other skb meta data out of BPF, thus having this scratch space generic and programmable allows for more flexibility than defining a direct 1:1 transfer of potentially new XDP members into skb (it's also more efficient as we don't need to initialize/handle each of such new members). The facility also works together with GRO aggregation. The scratch space at the head of the packet can be multiple of 4 byte up to 32 byte large. Drivers not yet supporting xdp->data_meta can simply be set up with xdp->data_meta as xdp->data + 1 as bpf_xdp_adjust_meta() will detect this and bail out, such that the subsequent match against xdp->data for later access is guaranteed to fail. The verifier treats xdp->data_meta/xdp->data the same way as we treat xdp->data/xdp->data_end pointer comparisons. The requirement for doing the compare against xdp->data is that it hasn't been modified from it's original address we got from ctx access. It may have a range marking already from prior successful xdp->data/xdp->data_end pointer comparisons though. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-26bpf: rename bpf_compute_data_end into bpf_compute_data_pointersDaniel Borkmann
Just do the rename into bpf_compute_data_pointers() as we'll add one more pointer here to recompute. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-25bpf: Optimize lpm trie deleteCraig Gallek
Before the delete operator was added, this datastructure maintained an invariant that intermediate nodes were only present when necessary to build the tree. This patch updates the delete operation to reinstate that invariant by removing unnecessary intermediate nodes after a node is removed and thus keeping the tree structure at a minimal size. Suggested-by: Daniel Mack <daniel@zonque.org> Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2017-09-19bpf: fix ri->map_owner pointer on bpf_prog_reallocDaniel Borkmann
Commit 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") passed the pointer to the prog itself to be loaded into r4 prior on bpf_redirect_map() helper call, so that we can store the owner into ri->map_owner out of the helper. Issue with that is that the actual address of the prog is still subject to change when subsequent rewrites occur that require slow path in bpf_prog_realloc() to alloc more memory, e.g. from patching inlining helper functions or constant blinding. Thus, we really need to take prog->aux as the address we're holding, which also works with prog clones as they share the same aux object. Instead of then fetching aux->prog during runtime, which could potentially incur cache misses due to false sharing, we are going to just use aux for comparison on the map owner. This will also keep the patchlet of the same size, and later check in xdp_map_invalid() only accesses read-only aux pointer from the prog, it's also in the same cacheline already from prior access when calling bpf_func. Fixes: 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-19bpf: do not disable/enable BH in bpf_map_free_id()Eric Dumazet
syzkaller reported following splat [1] Since hard irq are disabled by the caller, bpf_map_free_id() should not try to enable/disable BH. Another solution would be to change htab_map_delete_elem() to defer the free_htab_elem() call after raw_spin_unlock_irqrestore(&b->lock, flags), but this might be not enough to cover other code paths. [1] WARNING: CPU: 1 PID: 8052 at kernel/softirq.c:161 __local_bh_enable_ip +0x1e/0x160 kernel/softirq.c:161 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 8052 Comm: syz-executor1 Not tainted 4.13.0-next-20170915+ #23 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x417 kernel/panic.c:181 __warn+0x1c4/0x1d9 kernel/panic.c:542 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:261 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905 RIP: 0010:__local_bh_enable_ip+0x1e/0x160 kernel/softirq.c:161 RSP: 0018:ffff8801cdcd7748 EFLAGS: 00010046 RAX: 0000000000000082 RBX: 0000000000000201 RCX: 0000000000000000 RDX: 1ffffffff0b5933c RSI: 0000000000000201 RDI: ffffffff85ac99e0 RBP: ffff8801cdcd7758 R08: ffffffff85b87158 R09: 1ffff10039b9aec6 R10: ffff8801c99f24c0 R11: 0000000000000002 R12: ffffffff817b0b47 R13: dffffc0000000000 R14: ffff8801cdcd77e8 R15: 0000000000000001 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:361 [inline] bpf_map_free_id kernel/bpf/syscall.c:197 [inline] __bpf_map_put+0x267/0x320 kernel/bpf/syscall.c:227 bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:235 bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96 free_htab_elem+0xc3/0x1b0 kernel/bpf/hashtab.c:658 htab_map_delete_elem+0x74d/0x970 kernel/bpf/hashtab.c:1063 map_delete_elem kernel/bpf/syscall.c:633 [inline] SYSC_bpf kernel/bpf/syscall.c:1479 [inline] SyS_bpf+0x2188/0x46a0 kernel/bpf/syscall.c:1451 entry_SYSCALL_64_fastpath+0x1f/0xbe Fixes: f3f1c054c288 ("bpf: Introduce bpf_map ID") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-19bpf: Implement map_delete_elem for BPF_MAP_TYPE_LPM_TRIECraig Gallek
This is a simple non-recursive delete operation. It prunes paths of empty nodes in the tree, but it does not try to further compress the tree as nodes are removed. Signed-off-by: Craig Gallek <kraig@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-18bpf: devmap: pass on return value of bpf_map_precharge_memlockTobias Klauser
If bpf_map_precharge_memlock in dev_map_alloc, -ENOMEM is returned regardless of the actual error produced by bpf_map_precharge_memlock. Fix it by passing on the error returned by bpf_map_precharge_memlock. Also return -EINVAL instead of -ENOMEM if the page count overflow check fails. This makes dev_map_alloc match the behavior of other bpf maps' alloc functions wrt. return values. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-15bpf/verifier: reject BPF_ALU64|BPF_ENDEdward Cree
Neither ___bpf_prog_run nor the JITs accept it. Also adds a new test case. Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-08bpf: devmap, use cond_resched instead of cpu_relaxJohn Fastabend
Be a bit more friendly about waiting for flush bits to complete. Replace the cpu_relax() with a cond_resched(). Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-08bpf: add support for sockmap detach programsJohn Fastabend
The bpf map sockmap supports adding programs via attach commands. This patch adds the detach command to keep the API symmetric and allow users to remove previously added programs. Otherwise the user would have to delete the map and re-add it to get in this state. This also adds a series of additional tests to capture detach operation and also attaching/detaching invalid prog types. API note: socks will run (or not run) programs depending on the state of the map at the time the sock is added. We do not for example walk the map and remove programs from previously attached socks. Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-08bpf: don't select potentially stale ri->map from buggy xdp progsDaniel Borkmann
We can potentially run into a couple of issues with the XDP bpf_redirect_map() helper. The ri->map in the per CPU storage can become stale in several ways, mostly due to misuse, where we can then trigger a use after free on the map: i) prog A is calling bpf_redirect_map(), returning XDP_REDIRECT and running on a driver not supporting XDP_REDIRECT yet. The ri->map on that CPU becomes stale when the XDP program is unloaded on the driver, and a prog B loaded on a different driver which supports XDP_REDIRECT return code. prog B would have to omit calling to bpf_redirect_map() and just return XDP_REDIRECT, which would then access the freed map in xdp_do_redirect() since not cleared for that CPU. ii) prog A is calling bpf_redirect_map(), returning a code other than XDP_REDIRECT. prog A is then detached, which triggers release of the map. prog B is attached which, similarly as in i), would just return XDP_REDIRECT without having called bpf_redirect_map() and thus be accessing the freed map in xdp_do_redirect() since not cleared for that CPU. iii) prog A is attached to generic XDP, calling the bpf_redirect_map() helper and returning XDP_REDIRECT. xdp_do_generic_redirect() is currently not handling ri->map (will be fixed by Jesper), so it's not being reset. Later loading a e.g. native prog B which would, say, call bpf_xdp_redirect() and then returns XDP_REDIRECT would find in xdp_do_redirect() that a map was set and uses that causing use after free on map access. Fix thus needs to avoid accessing stale ri->map pointers, naive way would be to call a BPF function from drivers that just resets it to NULL for all XDP return codes but XDP_REDIRECT and including XDP_REDIRECT for drivers not supporting it yet (and let ri->map being handled in xdp_do_generic_redirect()). There is a less intrusive way w/o letting drivers call a reset for each BPF run. The verifier knows we're calling into bpf_xdp_redirect_map() helper, so it can do a small insn rewrite transparent to the prog itself in the sense that it fills R4 with a pointer to the own bpf_prog. We have that pointer at verification time anyway and R4 is allowed to be used as per calling convention we scratch R0 to R5 anyway, so they become inaccessible and program cannot read them prior to a write. Then, the helper would store the prog pointer in the current CPUs struct redirect_info. Later in xdp_do_*_redirect() we check whether the redirect_info's prog pointer is the same as passed xdp_prog pointer, and if that's the case then all good, since the prog holds a ref on the map anyway, so it is always valid at that point in time and must have a reference count of at least 1. If in the unlikely case they are not equal, it means we got a stale pointer, so we clear and bail out right there. Also do reset map and the owning prog in bpf_xdp_redirect(), so that bpf_xdp_redirect_map() and bpf_xdp_redirect() won't get mixed up, only the last call should take precedence. A tc bpf_redirect() doesn't use map anywhere yet, so no need to clear it there since never accessed in that layer. Note that in case the prog is released, and thus the map as well we're still under RCU read critical section at that time and have preemption disabled as well. Once we commit with the __dev_map_insert_ctx() from xdp_do_redirect_map() and set the map to ri->map_to_flush, we still wait for a xdp_do_flush_map() to finish in devmap dismantle time once flush_needed bit is set, so that is fine. Fixes: 97f91a7cf04f ("bpf: add bpf_redirect_map helper routine") Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-05bpf: fix numa_node validationEric Dumazet
syzkaller reported crashes in bpf map creation or map update [1] Problem is that nr_node_ids is a signed integer, NUMA_NO_NODE is also an integer, so it is very tempting to declare numa_node as a signed integer. This means the typical test to validate a user provided value : if (numa_node != NUMA_NO_NODE && (numa_node >= nr_node_ids || !node_online(numa_node))) must be written : if (numa_node != NUMA_NO_NODE && ((unsigned int)numa_node >= nr_node_ids || !node_online(numa_node))) [1] kernel BUG at mm/slab.c:3256! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 2946 Comm: syzkaller916108 Not tainted 4.13.0-rc7+ #35 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d2bc60c0 task.stack: ffff8801c0c90000 RIP: 0010:____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292 RSP: 0018:ffff8801c0c97638 EFLAGS: 00010096 RAX: ffffffffffff8b7b RBX: 0000000001080220 RCX: 0000000000000000 RDX: 00000000ffff8b7b RSI: 0000000001080220 RDI: ffff8801dac00040 RBP: ffff8801c0c976c0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8801c0c97620 R11: 0000000000000001 R12: ffff8801dac00040 R13: ffff8801dac00040 R14: 0000000000000000 R15: 00000000ffff8b7b FS: 0000000002119940(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001fec CR3: 00000001d2980000 CR4: 00000000001406f0 Call Trace: __do_kmalloc_node mm/slab.c:3688 [inline] __kmalloc_node+0x33/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:535 [inline] alloc_htab_elem+0x2a8/0x480 kernel/bpf/hashtab.c:740 htab_map_update_elem+0x740/0xb80 kernel/bpf/hashtab.c:820 map_update_elem kernel/bpf/syscall.c:587 [inline] SYSC_bpf kernel/bpf/syscall.c:1468 [inline] SyS_bpf+0x20c5/0x4c40 kernel/bpf/syscall.c:1443 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x440409 RSP: 002b:00007ffd1f1792b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440409 RDX: 0000000000000020 RSI: 0000000020006000 RDI: 0000000000000002 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401d70 R13: 0000000000401e00 R14: 0000000000000000 R15: 0000000000000000 Code: 83 c2 01 89 50 18 4c 03 70 08 e8 38 f4 ff ff 4d 85 f6 0f 85 3e ff ff ff 44 89 fe 4c 89 ef e8 94 fb ff ff 49 89 c6 e9 2b ff ff ff <0f> 0b 0f 0b 0f 0b 66 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 RIP: ____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292 RSP: ffff8801c0c97638 ---[ end trace d745f355da2e33ce ]--- Kernel panic - not syncing: Fatal exception Fixes: 96eabe7a40aa ("bpf: Allow selecting numa node during map creation") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01bpf: sockmap update/simplify memory accounting schemeJohn Fastabend
Instead of tracking wmem_queued and sk_mem_charge by incrementing in the verdict SK_REDIRECT paths and decrementing in the tx work path use skb_set_owner_w and sock_writeable helpers. This solves a few issues with the current code. First, in SK_REDIRECT inc on sk_wmem_queued and sk_mem_charge were being done without the peers sock lock being held. Under stress this can result in accounting errors when tx work and/or multiple verdict decisions are working on the peer psock. Additionally, this cleans up the code because we can rely on the default destructor to decrement memory accounting on kfree_skb. Also this will trigger sk_write_space when space becomes available on kfree_skb() which wasn't happening before and prevent __sk_free from being called until all in-flight packets are completed. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01bpf: Only set node->ref = 1 if it has not been setMartin KaFai Lau
This patch writes 'node->ref = 1' only if node->ref is 0. The number of lookups/s for a ~1M entries LRU map increased by ~30% (260097 to 343313). Other writes on 'node->ref = 0' is not changed. In those cases, the same cache line has to be changed anyway. First column: Size of the LRU hash Second column: Number of lookups/s Before: > echo "$((2**20+1)): $(./map_perf_test 1024 1 $((2**20+1)) 10000000 | awk '{print $3}')" 1048577: 260097 After: > echo "$((2**20+1)): $(./map_perf_test 1024 1 $((2**20+1)) 10000000 | awk '{print $3}')" 1048577: 343313 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01bpf: Inline LRU map lookupMartin KaFai Lau
Inline the lru map lookup to save the cost in making calls to bpf_map_lookup_elem() and htab_lru_map_lookup_elem(). Different LRU hash size is tested. The benefit diminishes when the cache miss starts to dominate in the bigger LRU hash. Considering the change is simple, it is still worth to optimize. First column: Size of the LRU hash Second column: Number of lookups/s Before: > for i in $(seq 9 20); do echo "$((2**i+1)): $(./map_perf_test 1024 1 $((2**i+1)) 10000000 | awk '{print $3}')"; done 513: 1132020 1025: 1056826 2049: 1007024 4097: 853298 8193: 742723 16385: 712600 32769: 688142 65537: 677028 131073: 619437 262145: 498770 524289: 316695 1048577: 260038 After: > for i in $(seq 9 20); do echo "$((2**i+1)): $(./map_perf_test 1024 1 $((2**i+1)) 10000000 | awk '{print $3}')"; done 513: 1221851 1025: 1144695 2049: 1049902 4097: 884460 8193: 773731 16385: 729673 32769: 721989 65537: 715530 131073: 671665 262145: 516987 524289: 321125 1048577: 260048 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28bpf: fix oops on allocation failureDan Carpenter
"err" is set to zero if bpf_map_area_alloc() fails so it means we return ERR_PTR(0) which is NULL. The caller, find_and_alloc_map(), is not expecting NULL returns and will oops. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28bpf: sockmap indicate sock events to listenersJohn Fastabend
After userspace pushes sockets into a sockmap it may not be receiving data (assuming stream_{parser|verdict} programs are attached). But, it may still want to manage the socks. A common pattern is to poll/select for a POLLRDHUP event so we can close the sock. This patch adds the logic to wake up these listeners. Also add TCP_SYN_SENT to the list of events to handle. We don't want to break the connection just because we happen to be in this state. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28bpf: harden sockmap program attach to ensure correct map typeJohn Fastabend
When attaching a program to sockmap we need to check map type is correct. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28bpf: sockmap add missing rcu_read_(un)lock in smap_data_readyJohn Fastabend
References to psock must be done inside RCU critical section. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28bpf: sockmap, remove STRPARSER map_flags and add multi-map supportJohn Fastabend
The addition of map_flags BPF_SOCKMAP_STRPARSER flags was to handle a specific use case where we want to have BPF parse program disabled on an entry in a sockmap. However, Alexei found the API a bit cumbersome and I agreed. Lets remove the STRPARSER flag and support the use case by allowing socks to be in multiple maps. This allows users to create two maps one with programs attached and one without. When socks are added to maps they now inherit any programs attached to the map. This is a nice generalization and IMO improves the API. The API rules are less ambiguous and do not need a flag: - When a sock is added to a sockmap we have two cases, i. The sock map does not have any attached programs so we can add sock to map without inheriting bpf programs. The sock may exist in 0 or more other maps. ii. The sock map has an attached BPF program. To avoid duplicate bpf programs we only add the sock entry if it does not have an existing strparser/verdict attached, returning -EBUSY if a program is already attached. Otherwise attach the program and inherit strparser/verdict programs from the sock map. This allows for socks to be in a multiple maps for redirects and inherit a BPF program from a single map. Also this patch simplifies the logic around BPF_{EXIST|NOEXIST|ANY} flags. In the original patch I tried to be extra clever and only update map entries when necessary. Now I've decided the complexity is not worth it. If users constantly update an entry with the same sock for no reason (i.e. update an entry without actually changing any parameters on map or sock) we still do an alloc/release. Using this and allowing multiple entries of a sock to exist in a map the logic becomes much simpler. Note: Now that multiple maps are supported the "maps" pointer called when a socket is closed becomes a list of maps to remove the sock from. To keep the map up to date when a sock is added to the sockmap we must add the map/elem in the list. Likewise when it is removed we must remove it from the list. This results in searching the per psock list on delete operation. On TCP_CLOSE events we walk the list and remove the psock from all map/entry locations. I don't see any perf implications in this because at most I have a psock in two maps. If a psock were to be in many maps its possibly this might be noticeable on delete but I can't think of a reason to dup a psock in many maps. The sk_callback_lock is used to protect read/writes to the list. This was convenient because in all locations we were taking the lock anyways just after working on the list. Also the lock is per sock so in normal cases we shouldn't see any contention. Suggested-by: Alexei Starovoitov <ast@kernel.org> Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28bpf: convert sockmap field attach_bpf_fd2 to typeJohn Fastabend
In the initial sockmap API we provided strparser and verdict programs using a single attach command by extending the attach API with a the attach_bpf_fd2 field. However, if we add other programs in the future we will be adding a field for every new possible type, attach_bpf_fd(3,4,..). This seems a bit clumsy for an API. So lets push the programs using two new type fields. BPF_SK_SKB_STREAM_PARSER BPF_SK_SKB_STREAM_VERDICT This has the advantage of having a readable name and can easily be extended in the future. Updates to samples and sockmap included here also generalize tests slightly to support upcoming patch for multiple map support. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Suggested-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24strparser: initialize all callbacksEric Biggers
commit bbb03029a899 ("strparser: Generalize strparser") added more function pointers to 'struct strp_callbacks'; however, kcm_attach() was not updated to initialize them. This could cause the ->lock() and/or ->unlock() function pointers to be set to garbage values, causing a crash in strp_work(). Fix the bug by moving the callback structs into static memory, so unspecified members are zeroed. Also constify them while we're at it. This bug was found by syzkaller, which encountered the following splat: IP: 0x55 PGD 3b1ca067 P4D 3b1ca067 PUD 3b12f067 PMD 0 Oops: 0010 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 2 PID: 1194 Comm: kworker/u8:1 Not tainted 4.13.0-rc4-next-20170811 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: kstrp strp_work task: ffff88006bb0e480 task.stack: ffff88006bb10000 RIP: 0010:0x55 RSP: 0018:ffff88006bb17540 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88006ce4bd60 RCX: 0000000000000000 RDX: 1ffff1000d9c97bd RSI: 0000000000000000 RDI: ffff88006ce4bc48 RBP: ffff88006bb17558 R08: ffffffff81467ab2 R09: 0000000000000000 R10: ffff88006bb17438 R11: ffff88006bb17940 R12: ffff88006ce4bc48 R13: ffff88003c683018 R14: ffff88006bb17980 R15: ffff88003c683000 FS: 0000000000000000(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000055 CR3: 000000003c145000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2098 worker_thread+0x223/0x1860 kernel/workqueue.c:2233 kthread+0x35e/0x430 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Code: Bad RIP value. RIP: 0x55 RSP: ffff88006bb17540 CR2: 0000000000000055 ---[ end trace f0e4920047069cee ]--- Here is a C reproducer (requires CONFIG_BPF_SYSCALL=y and CONFIG_AF_KCM=y): #include <linux/bpf.h> #include <linux/kcm.h> #include <linux/types.h> #include <stdint.h> #include <sys/ioctl.h> #include <sys/socket.h> #include <sys/syscall.h> #include <unistd.h> static const struct bpf_insn bpf_insns[3] = { { .code = 0xb7 }, /* BPF_MOV64_IMM(0, 0) */ { .code = 0x95 }, /* BPF_EXIT_INSN() */ }; static const union bpf_attr bpf_attr = { .prog_type = 1, .insn_cnt = 2, .insns = (uintptr_t)&bpf_insns, .license = (uintptr_t)"", }; int main(void) { int bpf_fd = syscall(__NR_bpf, BPF_PROG_LOAD, &bpf_attr, sizeof(bpf_attr)); int inet_fd = socket(AF_INET, SOCK_STREAM, 0); int kcm_fd = socket(AF_KCM, SOCK_DGRAM, 0); ioctl(kcm_fd, SIOCKCMATTACH, &(struct kcm_attach) { .fd = inet_fd, .bpf_fd = bpf_fd }); } Fixes: bbb03029a899 ("strparser: Generalize strparser") Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Tom Herbert <tom@quantonium.net> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-23bpf: netdev is never null in __dev_map_flushDaniel Borkmann
No need to test for it in fast-path, every dev in bpf_dtab_netdev is guaranteed to be non-NULL, otherwise dev_map_update_elem() will fail in the first place. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-23bpf/verifier: document liveness analysisEdward Cree
The liveness tracking algorithm is quite subtle; add comments to explain it. Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-23bpf/verifier: remove varlen_map_value_access flagEdward Cree
The optimisation it does is broken when the 'new' register value has a variable offset and the 'old' was constant. I broke it with my pointer types unification (see Fixes tag below), before which the 'new' value would have type PTR_TO_MAP_VALUE_ADJ and would thus not compare equal; other changes in that patch mean that its original behaviour (ignore min/max values) cannot be restored. Tests on a sample set of cilium programs show no change in count of processed instructions. Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>