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2021-05-03bpf: Fix leakage of uninitialized bpf stack under speculationDaniel Borkmann
The current implemented mechanisms to mitigate data disclosure under speculation mainly address stack and map value oob access from the speculative domain. However, Piotr discovered that uninitialized BPF stack is not protected yet, and thus old data from the kernel stack, potentially including addresses of kernel structures, could still be extracted from that 512 bytes large window. The BPF stack is special compared to map values since it's not zero initialized for every program invocation, whereas map values /are/ zero initialized upon their initial allocation and thus cannot leak any prior data in either domain. In the non-speculative domain, the verifier ensures that every stack slot read must have a prior stack slot write by the BPF program to avoid such data leaking issue. However, this is not enough: for example, when the pointer arithmetic operation moves the stack pointer from the last valid stack offset to the first valid offset, the sanitation logic allows for any intermediate offsets during speculative execution, which could then be used to extract any restricted stack content via side-channel. Given for unprivileged stack pointer arithmetic the use of unknown but bounded scalars is generally forbidden, we can simply turn the register-based arithmetic operation into an immediate-based arithmetic operation without the need for masking. This also gives the benefit of reducing the needed instructions for the operation. Given after the work in 7fedb63a8307 ("bpf: Tighten speculative pointer arithmetic mask"), the aux->alu_limit already holds the final immediate value for the offset register with the known scalar. Thus, a simple mov of the immediate to AX register with using AX as the source for the original instruction is sufficient and possible now in this case. Reported-by: Piotr Krysiuk <piotras@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Piotr Krysiuk <piotras@gmail.com> Reviewed-by: Piotr Krysiuk <piotras@gmail.com> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-05-03bpf: Fix masking negation logic upon negative dst registerDaniel Borkmann
The negation logic for the case where the off_reg is sitting in the dst register is not correct given then we cannot just invert the add to a sub or vice versa. As a fix, perform the final bitwise and-op unconditionally into AX from the off_reg, then move the pointer from the src to dst and finally use AX as the source for the original pointer arithmetic operation such that the inversion yields a correct result. The single non-AX mov in between is possible given constant blinding is retaining it as it's not an immediate based operation. Fixes: 979d63d50c0c ("bpf: prevent out of bounds speculation on pointer arithmetic") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Piotr Krysiuk <piotras@gmail.com> Reviewed-by: Piotr Krysiuk <piotras@gmail.com> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-29Merge tag 'net-next-5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - bpf: - allow bpf programs calling kernel functions (initially to reuse TCP congestion control implementations) - enable task local storage for tracing programs - remove the need to store per-task state in hash maps, and allow tracing programs access to task local storage previously added for BPF_LSM - add bpf_for_each_map_elem() helper, allowing programs to walk all map elements in a more robust and easier to verify fashion - sockmap: support UDP and cross-protocol BPF_SK_SKB_VERDICT redirection - lpm: add support for batched ops in LPM trie - add BTF_KIND_FLOAT support - mostly to allow use of BTF on s390 which has floats in its headers files - improve BPF syscall documentation and extend the use of kdoc parsing scripts we already employ for bpf-helpers - libbpf, bpftool: support static linking of BPF ELF files - improve support for encapsulation of L2 packets - xdp: restructure redirect actions to avoid a runtime lookup, improving performance by 4-8% in microbenchmarks - xsk: build skb by page (aka generic zerocopy xmit) - improve performance of software AF_XDP path by 33% for devices which don't need headers in the linear skb part (e.g. virtio) - nexthop: resilient next-hop groups - improve path stability on next-hops group changes (incl. offload for mlxsw) - ipv6: segment routing: add support for IPv4 decapsulation - icmp: add support for RFC 8335 extended PROBE messages - inet: use bigger hash table for IP ID generation - tcp: deal better with delayed TX completions - make sure we don't give up on fast TCP retransmissions only because driver is slow in reporting that it completed transmitting the original - tcp: reorder tcp_congestion_ops for better cache locality - mptcp: - add sockopt support for common TCP options - add support for common TCP msg flags - include multiple address ids in RM_ADDR - add reset option support for resetting one subflow - udp: GRO L4 improvements - improve 'forward' / 'frag_list' co-existence with UDP tunnel GRO, allowing the first to take place correctly even for encapsulated UDP traffic - micro-optimize dev_gro_receive() and flow dissection, avoid retpoline overhead on VLAN and TEB GRO - use less memory for sysctls, add a new sysctl type, to allow using u8 instead of "int" and "long" and shrink networking sysctls - veth: allow GRO without XDP - this allows aggregating UDP packets before handing them off to routing, bridge, OvS, etc. - allow specifing ifindex when device is moved to another namespace - netfilter: - nft_socket: add support for cgroupsv2 - nftables: add catch-all set element - special element used to define a default action in case normal lookup missed - use net_generic infra in many modules to avoid allocating per-ns memory unnecessarily - xps: improve the xps handling to avoid potential out-of-bound accesses and use-after-free when XPS change race with other re-configuration under traffic - add a config knob to turn off per-cpu netdev refcnt to catch underflows in testing Device APIs: - add WWAN subsystem to organize the WWAN interfaces better and hopefully start driving towards more unified and vendor- independent APIs - ethtool: - add interface for reading IEEE MIB stats (incl. mlx5 and bnxt support) - allow network drivers to dump arbitrary SFP EEPROM data, current offset+length API was a poor fit for modern SFP which define EEPROM in terms of pages (incl. mlx5 support) - act_police, flow_offload: add support for packet-per-second policing (incl. offload for nfp) - psample: add additional metadata attributes like transit delay for packets sampled from switch HW (and corresponding egress and policy-based sampling in the mlxsw driver) - dsa: improve support for sandwiched LAGs with bridge and DSA - netfilter: - flowtable: use direct xmit in topologies with IP forwarding, bridging, vlans etc. - nftables: counter hardware offload support - Bluetooth: - improvements for firmware download w/ Intel devices - add support for reading AOSP vendor capabilities - add support for virtio transport driver - mac80211: - allow concurrent monitor iface and ethernet rx decap - set priority and queue mapping for injected frames - phy: add support for Clause-45 PHY Loopback - pci/iov: add sysfs MSI-X vector assignment interface to distribute MSI-X resources to VFs (incl. mlx5 support) New hardware/drivers: - dsa: mv88e6xxx: add support for Marvell mv88e6393x - 11-port Ethernet switch with 8x 1-Gigabit Ethernet and 3x 10-Gigabit interfaces. - dsa: support for legacy Broadcom tags used on BCM5325, BCM5365 and BCM63xx switches - Microchip KSZ8863 and KSZ8873; 3x 10/100Mbps Ethernet switches - ath11k: support for QCN9074 a 802.11ax device - Bluetooth: Broadcom BCM4330 and BMC4334 - phy: Marvell 88X2222 transceiver support - mdio: add BCM6368 MDIO mux bus controller - r8152: support RTL8153 and RTL8156 (USB Ethernet) chips - mana: driver for Microsoft Azure Network Adapter (MANA) - Actions Semi Owl Ethernet MAC - can: driver for ETAS ES58X CAN/USB interfaces Pure driver changes: - add XDP support to: enetc, igc, stmmac - add AF_XDP support to: stmmac - virtio: - page_to_skb() use build_skb when there's sufficient tailroom (21% improvement for 1000B UDP frames) - support XDP even without dedicated Tx queues - share the Tx queues with the stack when necessary - mlx5: - flow rules: add support for mirroring with conntrack, matching on ICMP, GTP, flex filters and more - support packet sampling with flow offloads - persist uplink representor netdev across eswitch mode changes - allow coexistence of CQE compression and HW time-stamping - add ethtool extended link error state reporting - ice, iavf: support flow filters, UDP Segmentation Offload - dpaa2-switch: - move the driver out of staging - add spanning tree (STP) support - add rx copybreak support - add tc flower hardware offload on ingress traffic - ionic: - implement Rx page reuse - support HW PTP time-stamping - octeon: support TC hardware offloads - flower matching on ingress and egress ratelimitting. - stmmac: - add RX frame steering based on VLAN priority in tc flower - support frame preemption (FPE) - intel: add cross time-stamping freq difference adjustment - ocelot: - support forwarding of MRP frames in HW - support multiple bridges - support PTP Sync one-step timestamping - dsa: mv88e6xxx, dpaa2-switch: offload bridge port flags like learning, flooding etc. - ipa: add IPA v4.5, v4.9 and v4.11 support (Qualcomm SDX55, SM8350, SC7280 SoCs) - mt7601u: enable TDLS support - mt76: - add support for 802.3 rx frames (mt7915/mt7615) - mt7915 flash pre-calibration support - mt7921/mt7663 runtime power management fixes" * tag 'net-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2451 commits) net: selftest: fix build issue if INET is disabled net: netrom: nr_in: Remove redundant assignment to ns net: tun: Remove redundant assignment to ret net: phy: marvell: add downshift support for M88E1240 net: dsa: ksz: Make reg_mib_cnt a u8 as it never exceeds 255 net/sched: act_ct: Remove redundant ct get and check icmp: standardize naming of RFC 8335 PROBE constants bpf, selftests: Update array map tests for per-cpu batched ops bpf: Add batched ops support for percpu array bpf: Implement formatted output helpers with bstr_printf seq_file: Add a seq_bprintf function sfc: adjust efx->xdp_tx_queue_count with the real number of initialized queues net:nfc:digital: Fix a double free in digital_tg_recv_dep_req net: fix a concurrency bug in l2tp_tunnel_register() net/smc: Remove redundant assignment to rc mpls: Remove redundant assignment to err llc2: Remove redundant assignment to rc net/tls: Remove redundant initialization of record rds: Remove redundant assignment to nr_sig dt-bindings: net: mdio-gpio: add compatible for microchip,mdio-smi0 ...
2021-04-28bpf: Add batched ops support for percpu arrayPedro Tammela
Uses the already in-place infrastructure provided by the 'generic_map_*_batch' functions. No tweak was needed as it transparently handles the percpu variant. As arrays don't have delete operations, let it return a error to user space (default behaviour). Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210424214510.806627-2-pctammela@mojatatu.com
2021-04-27bpf: Implement formatted output helpers with bstr_printfFlorent Revest
BPF has three formatted output helpers: bpf_trace_printk, bpf_seq_printf and bpf_snprintf. Their signatures specify that all arguments are provided from the BPF world as u64s (in an array or as registers). All of these helpers are currently implemented by calling functions such as snprintf() whose signatures take a variable number of arguments, then placed in a va_list by the compiler to call vsnprintf(). "d9c9e4db bpf: Factorize bpf_trace_printk and bpf_seq_printf" introduced a bpf_printf_prepare function that fills an array of u64 sanitized arguments with an array of "modifiers" which indicate what the "real" size of each argument should be (given by the format specifier). The BPF_CAST_FMT_ARG macro consumes these arrays and casts each argument to its real size. However, the C promotion rules implicitely cast them all back to u64s. Therefore, the arguments given to snprintf are u64s and the va_list constructed by the compiler will use 64 bits for each argument. On 64 bit machines, this happens to work well because 32 bit arguments in va_lists need to occupy 64 bits anyway, but on 32 bit architectures this breaks the layout of the va_list expected by the called function and mangles values. In "88a5c690b6 bpf: fix bpf_trace_printk on 32 bit archs", this problem had been solved for bpf_trace_printk only with a "horrid workaround" that emitted multiple calls to trace_printk where each call had different argument types and generated different va_list layouts. One of the call would be dynamically chosen at runtime. This was ok with the 3 arguments that bpf_trace_printk takes but bpf_seq_printf and bpf_snprintf accept up to 12 arguments. Because this approach scales code exponentially, it is not a viable option anymore. Because the promotion rules are part of the language and because the construction of a va_list is an arch-specific ABI, it's best to just avoid variadic arguments and va_lists altogether. Thankfully the kernel's snprintf() has an alternative in the form of bstr_printf() that accepts arguments in a "binary buffer representation". These binary buffers are currently created by vbin_printf and used in the tracing subsystem to split the cost of printing into two parts: a fast one that only dereferences and remembers values, and a slower one, called later, that does the pretty-printing. This patch refactors bpf_printf_prepare to construct binary buffers of arguments consumable by bstr_printf() instead of arrays of arguments and modifiers. This gets rid of BPF_CAST_FMT_ARG and greatly simplifies the bpf_printf_prepare usage but there are a few gotchas that change how bpf_printf_prepare needs to do things. Currently, bpf_printf_prepare uses a per cpu temporary buffer as a generic storage for strings and IP addresses. With this refactoring, the temporary buffers now holds all the arguments in a structured binary format. To comply with the format expected by bstr_printf, certain format specifiers also need to be pre-formatted: %pB and %pi6/%pi4/%pI4/%pI6. Because vsnprintf subroutines for these specifiers are hard to expose, we pre-format these arguments with calls to snprintf(). Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210427174313.860948-3-revest@chromium.org
2021-04-27Merge tag 'selinux-pr-20210426' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: - Add support for measuring the SELinux state and policy capabilities using IMA. - A handful of SELinux/NFS patches to compare the SELinux state of one mount with a set of mount options. Olga goes into more detail in the patch descriptions, but this is important as it allows more flexibility when using NFS and SELinux context mounts. - Properly differentiate between the subjective and objective LSM credentials; including support for the SELinux and Smack. My clumsy attempt at a proper fix for AppArmor didn't quite pass muster so John is working on a proper AppArmor patch, in the meantime this set of patches shouldn't change the behavior of AppArmor in any way. This change explains the bulk of the diffstat beyond security/. - Fix a problem where we were not properly terminating the permission list for two SELinux object classes. * tag 'selinux-pr-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: add proper NULL termination to the secclass_map permissions smack: differentiate between subjective and objective task credentials selinux: clarify task subjective and objective credentials lsm: separate security_task_getsecid() into subjective and objective variants nfs: account for selinux security context when deciding to share superblock nfs: remove unneeded null check in nfs_fill_super() lsm,selinux: add new hook to compare new mount to an existing mount selinux: fix misspellings using codespell tool selinux: fix misspellings using codespell tool selinux: measure state and policy capabilities selinux: Allow context mounts for unpriviliged overlayfs
2021-04-27bpf, cpumap: Bulk skb using netif_receive_skb_listLorenzo Bianconi
Rely on netif_receive_skb_list routine to send skbs converted from xdp_frames in cpu_map_kthread_run in order to improve i-cache usage. The proposed patch has been tested running xdp_redirect_cpu bpf sample available in the kernel tree that is used to redirect UDP frames from ixgbe driver to a cpumap entry and then to the networking stack. UDP frames are generated using pktgen. Packets are discarded by the UDP layer. $ xdp_redirect_cpu --cpu <cpu> --progname xdp_cpu_map0 --dev <eth> bpf-next: ~2.35Mpps bpf-next + cpumap skb-list: ~2.72Mpps Rename drops counter in kmem_alloc_drops since now it reports just kmem_cache_alloc_bulk failures Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/c729f83e5d7482d9329e0f165bdbe5adcefd1510.1619169700.git.lorenzo@kernel.org
2021-04-27bpf: Fix propagation of 32 bit unsigned bounds from 64 bit boundsDaniel Borkmann
Similarly as b02709587ea3 ("bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds."), we also need to fix the propagation of 32 bit unsigned bounds from 64 bit counterparts. That is, really only set the u32_{min,max}_value when /both/ {umin,umax}_value safely fit in 32 bit space. For example, the register with a umin_value == 1 does /not/ imply that u32_min_value is also equal to 1, since umax_value could be much larger than 32 bit subregister can hold, and thus u32_min_value is in the interval [0,1] instead. Before fix, invalid tracking result of R2_w=inv1: [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smin_value=-9223372036854775807,smax_value=9223372032559808513,umin_value=1,umax_value=18446744069414584321,var_off=(0x1; 0xffffffff00000000),s32_min_value=1,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv1 R10=fp0 [...] After fix, correct tracking result of R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)): [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smax_value=9223372032559808513,umax_value=18446744069414584321,var_off=(0x0; 0xffffffff00000001),s32_min_value=0,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)) R10=fp0 [...] Thus, same issue as in b02709587ea3 holds for unsigned subregister tracking. Also, align __reg64_bound_u32() similarly to __reg64_bound_s32() as done in b02709587ea3 to make them uniform again. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Manfred Paul (@_manfp) Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-25bpf: Allow trampoline re-attach for tracing and lsm programsJiri Olsa
Currently we don't allow re-attaching of trampolines. Once it's detached, it can't be re-attach even when the program is still loaded. Adding the possibility to re-attach the loaded tracing and lsm programs. Fixing missing unlock with proper cleanup goto jump reported by Julia. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210414195147.1624932-2-jolsa@kernel.org
2021-04-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-04-23 The following pull-request contains BPF updates for your *net-next* tree. We've added 69 non-merge commits during the last 22 day(s) which contain a total of 69 files changed, 3141 insertions(+), 866 deletions(-). The main changes are: 1) Add BPF static linker support for extern resolution of global, from Andrii. 2) Refine retval for bpf_get_task_stack helper, from Dave. 3) Add a bpf_snprintf helper, from Florent. 4) A bunch of miscellaneous improvements from many developers. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-23bpf: Remove unnecessary map checks for ARG_PTR_TO_CONST_STRFlorent Revest
reg->type is enforced by check_reg_type() and map should never be NULL (it would already have been dereferenced anyway) so these checks are unnecessary. Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210422235543.4007694-3-revest@chromium.org
2021-04-23bpf: Notify user if we ever hit a bpf_snprintf verifier bugFlorent Revest
In check_bpf_snprintf_call(), a map_direct_value_addr() of the fmt map should never fail because it has already been checked by ARG_PTR_TO_CONST_STR. But if it ever fails, it's better to error out with an explicit debug message rather than silently fail. Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210422235543.4007694-2-revest@chromium.org
2021-04-19bpf: Refine retval for bpf_get_task_stack helperDave Marchevsky
Verifier can constrain the min/max bounds of bpf_get_task_stack's return value more tightly than the default tnum_unknown. Like bpf_get_stack, return value is num bytes written into a caller-supplied buf, or error, so do_refine_retval_range will work. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210416204704.2816874-2-davemarchevsky@fb.com
2021-04-19bpf: Add a bpf_snprintf helperFlorent Revest
The implementation takes inspiration from the existing bpf_trace_printk helper but there are a few differences: To allow for a large number of format-specifiers, parameters are provided in an array, like in bpf_seq_printf. Because the output string takes two arguments and the array of parameters also takes two arguments, the format string needs to fit in one argument. Thankfully, ARG_PTR_TO_CONST_STR is guaranteed to point to a zero-terminated read-only map so we don't need a format string length arg. Because the format-string is known at verification time, we also do a first pass of format string validation in the verifier logic. This makes debugging easier. Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-4-revest@chromium.org
2021-04-19bpf: Add a ARG_PTR_TO_CONST_STR argument typeFlorent Revest
This type provides the guarantee that an argument is going to be a const pointer to somewhere in a read-only map value. It also checks that this pointer is followed by a zero character before the end of the map value. Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-3-revest@chromium.org
2021-04-19bpf: Factorize bpf_trace_printk and bpf_seq_printfFlorent Revest
Two helpers (trace_printk and seq_printf) have very similar implementations of format string parsing and a third one is coming (snprintf). To avoid code duplication and make the code easier to maintain, this moves the operations associated with format string parsing (validation and argument sanitization) into one generic function. The implementation of the two existing helpers already drifted quite a bit so unifying them entailed a lot of changes: - bpf_trace_printk always expected fmt[fmt_size] to be the terminating NULL character, this is no longer true, the first 0 is terminating. - bpf_trace_printk now supports %% (which produces the percentage char). - bpf_trace_printk now skips width formating fields. - bpf_trace_printk now supports the X modifier (capital hexadecimal). - bpf_trace_printk now supports %pK, %px, %pB, %pi4, %pI4, %pi6 and %pI6 - argument casting on 32 bit has been simplified into one macro and using an enum instead of obscure int increments. - bpf_seq_printf now uses bpf_trace_copy_string instead of strncpy_from_kernel_nofault and handles the %pks %pus specifiers. - bpf_seq_printf now prints longs correctly on 32 bit architectures. - both were changed to use a global per-cpu tmp buffer instead of one stack buffer for trace_printk and 6 small buffers for seq_printf. - to avoid per-cpu buffer usage conflict, these helpers disable preemption while the per-cpu buffer is in use. - both helpers now support the %ps and %pS specifiers to print symbols. The implementation is also moved from bpf_trace.c to helpers.c because the upcoming bpf_snprintf helper will be made available to all BPF programs and will need it. Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-2-revest@chromium.org
2021-04-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c - keep the ZC code, drop the code related to reinit net/bridge/netfilter/ebtables.c - fix build after move to net_generic Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-16bpf: Tighten speculative pointer arithmetic maskDaniel Borkmann
This work tightens the offset mask we use for unprivileged pointer arithmetic in order to mitigate a corner case reported by Piotr and Benedict where in the speculative domain it is possible to advance, for example, the map value pointer by up to value_size-1 out-of-bounds in order to leak kernel memory via side-channel to user space. Before this change, the computed ptr_limit for retrieve_ptr_limit() helper represents largest valid distance when moving pointer to the right or left which is then fed as aux->alu_limit to generate masking instructions against the offset register. After the change, the derived aux->alu_limit represents the largest potential value of the offset register which we mask against which is just a narrower subset of the former limit. For minimal complexity, we call sanitize_ptr_alu() from 2 observation points in adjust_ptr_min_max_vals(), that is, before and after the simulated alu operation. In the first step, we retieve the alu_state and alu_limit before the operation as well as we branch-off a verifier path and push it to the verification stack as we did before which checks the dst_reg under truncation, in other words, when the speculative domain would attempt to move the pointer out-of-bounds. In the second step, we retrieve the new alu_limit and calculate the absolute distance between both. Moreover, we commit the alu_state and final alu_limit via update_alu_sanitation_state() to the env's instruction aux data, and bail out from there if there is a mismatch due to coming from different verification paths with different states. Reported-by: Piotr Krysiuk <piotras@gmail.com> Reported-by: Benedict Schlueter <benedict.schlueter@rub.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Benedict Schlueter <benedict.schlueter@rub.de>
2021-04-16bpf: Move sanitize_val_alu out of op switchDaniel Borkmann
Add a small sanitize_needed() helper function and move sanitize_val_alu() out of the main opcode switch. In upcoming work, we'll move sanitize_ptr_alu() as well out of its opcode switch so this helps to streamline both. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16bpf: Refactor and streamline bounds check into helperDaniel Borkmann
Move the bounds check in adjust_ptr_min_max_vals() into a small helper named sanitize_check_bounds() in order to simplify the former a bit. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16bpf: Improve verifier error messages for usersDaniel Borkmann
Consolidate all error handling and provide more user-friendly error messages from sanitize_ptr_alu() and sanitize_val_alu(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16bpf: Rework ptr_limit into alu_limit and add common error pathDaniel Borkmann
Small refactor with no semantic changes in order to consolidate the max ptr_limit boundary check. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16bpf: Ensure off_reg has no mixed signed bounds for all typesDaniel Borkmann
The mixed signed bounds check really belongs into retrieve_ptr_limit() instead of outside of it in adjust_ptr_min_max_vals(). The reason is that this check is not tied to PTR_TO_MAP_VALUE only, but to all pointer types that we handle in retrieve_ptr_limit() and given errors from the latter propagate back to adjust_ptr_min_max_vals() and lead to rejection of the program, it's a better place to reside to avoid anything slipping through for future types. The reason why we must reject such off_reg is that we otherwise would not be able to derive a mask, see details in 9d7eceede769 ("bpf: restrict unknown scalars of mixed signed bounds for unprivileged"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16bpf: Move off_reg into sanitize_ptr_aluDaniel Borkmann
Small refactor to drag off_reg into sanitize_ptr_alu(), so we later on can use off_reg for generalizing some of the checks for all pointer types. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16bpf: Use correct permission flag for mixed signed bounds arithmeticDaniel Borkmann
We forbid adding unknown scalars with mixed signed bounds due to the spectre v1 masking mitigation. Hence this also needs bypass_spec_v1 flag instead of allow_ptr_leaks. Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-13bpf: Return target info when a tracing bpf_link is queriedToke Høiland-Jørgensen
There is currently no way to discover the target of a tracing program attachment after the fact. Add this information to bpf_link_info and return it when querying the bpf_link fd. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210413091607.58945-1-toke@redhat.com
2021-04-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Conflicts: MAINTAINERS - keep Chandrasekar drivers/net/ethernet/mellanox/mlx5/core/en_main.c - simple fix + trust the code re-added to param.c in -next is fine include/linux/bpf.h - trivial include/linux/ethtool.h - trivial, fix kdoc while at it include/linux/skmsg.h - move to relevant place in tcp.c, comment re-wrapped net/core/skmsg.c - add the sk = sk // sk = NULL around calls net/tipc/crypto.c - trivial Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-06bpf, inode: Remove second initialization of the bpf_preload_lockMuhammad Usama Anjum
bpf_preload_lock is already defined with DEFINE_MUTEX(). There is no need to initialize it again. Remove the extraneous initialization. Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210405194904.GA148013@LEGION
2021-04-03bpf: Remove unused parameter from ___bpf_prog_runHe Fengqing
'stack' parameter is not used in ___bpf_prog_run() after f696b8f471ec ("bpf: split bpf core interpreter"), the base address have been set to FP reg. So consequently remove it. Signed-off-by: He Fengqing <hefengqing@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210331075135.3850782-1-hefengqing@huawei.com
2021-04-01bpf: program: Refuse non-O_RDWR flags in BPF_OBJ_GETLorenz Bauer
As for bpf_link, refuse creating a non-O_RDWR fd. Since program fds currently don't allow modifications this is a precaution, not a straight up bug fix. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210326160501.46234-2-lmb@cloudflare.com
2021-04-01bpf: link: Refuse non-O_RDWR flags in BPF_OBJ_GETLorenz Bauer
Invoking BPF_OBJ_GET on a pinned bpf_link checks the path access permissions based on file_flags, but the returned fd ignores flags. This means that any user can acquire a "read-write" fd for a pinned link with mode 0664 by invoking BPF_OBJ_GET with BPF_F_RDONLY in file_flags. The fd can be used to invoke BPF_LINK_DETACH, etc. Fix this by refusing non-O_RDWR flags in BPF_OBJ_GET. This works because OBJ_GET by default returns a read write mapping and libbpf doesn't expose a way to override this behaviour for programs and links. Fixes: 70ed506c3bbc ("bpf: Introduce pinnable bpf_link abstraction") Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210326160501.46234-1-lmb@cloudflare.com
2021-04-01bpf: Refcount task stack in bpf_get_task_stackDave Marchevsky
On x86 the struct pt_regs * grabbed by task_pt_regs() points to an offset of task->stack. The pt_regs are later dereferenced in __bpf_get_stack (e.g. by user_mode() check). This can cause a fault if the task in question exits while bpf_get_task_stack is executing, as warned by task_stack_page's comment: * When accessing the stack of a non-current task that might exit, use * try_get_task_stack() instead. task_stack_page will return a pointer * that could get freed out from under you. Taking the comment's advice and using try_get_task_stack() and put_task_stack() to hold task->stack refcount, or bail early if it's already 0. Incrementing stack_refcount will ensure the task's stack sticks around while we're using its data. I noticed this bug while testing a bpf task iter similar to bpf_iter_task_stack in selftests, except mine grabbed user stack, and getting intermittent crashes, which resulted in dumps like: BUG: unable to handle page fault for address: 0000000000003fe0 \#PF: supervisor read access in kernel mode \#PF: error_code(0x0000) - not-present page RIP: 0010:__bpf_get_stack+0xd0/0x230 <snip...> Call Trace: bpf_prog_0a2be35c092cb190_get_task_stacks+0x5d/0x3ec bpf_iter_run_prog+0x24/0x81 __task_seq_show+0x58/0x80 bpf_seq_read+0xf7/0x3d0 vfs_read+0x91/0x140 ksys_read+0x59/0xd0 do_syscall_64+0x48/0x120 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: fa28dcb82a38 ("bpf: Introduce helper bpf_get_task_stack()") Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210401000747.3648767-1-davemarchevsky@fb.com
2021-04-01sock_map: Introduce BPF_SK_SKB_VERDICTCong Wang
Reusing BPF_SK_SKB_STREAM_VERDICT is possible but its name is confusing and more importantly we still want to distinguish them from user-space. So we can just reuse the stream verdict code but introduce a new type of eBPF program, skb_verdict. Users are not allowed to attach stream_verdict and skb_verdict programs to the same map. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210331023237.41094-10-xiyou.wangcong@gmail.com
2021-03-30bpf: Remove redundant assignment of variable idColin Ian King
The variable id is being assigned a value that is never read, the assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210326194348.623782-1-colin.king@canonical.com
2021-03-26bpf: Support bpf program calling kernel functionMartin KaFai Lau
This patch adds support to BPF verifier to allow bpf program calling kernel function directly. The use case included in this set is to allow bpf-tcp-cc to directly call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()"). Those functions have already been used by some kernel tcp-cc implementations. This set will also allow the bpf-tcp-cc program to directly call the kernel tcp-cc implementation, For example, a bpf_dctcp may only want to implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly from the kernel tcp_dctcp.c instead of reimplementing (or copy-and-pasting) them. The tcp-cc kernel functions mentioned above will be white listed for the struct_ops bpf-tcp-cc programs to use in a later patch. The white listed functions are not bounded to a fixed ABI contract. Those functions have already been used by the existing kernel tcp-cc. If any of them has changed, both in-tree and out-of-tree kernel tcp-cc implementations have to be changed. The same goes for the struct_ops bpf-tcp-cc programs which have to be adjusted accordingly. This patch is to make the required changes in the bpf verifier. First change is in btf.c, it adds a case in "btf_check_func_arg_match()". When the passed in "btf->kernel_btf == true", it means matching the verifier regs' states with a kernel function. This will handle the PTR_TO_BTF_ID reg. It also maps PTR_TO_SOCK_COMMON, PTR_TO_SOCKET, and PTR_TO_TCP_SOCK to its kernel's btf_id. In the later libbpf patch, the insn calling a kernel function will look like: insn->code == (BPF_JMP | BPF_CALL) insn->src_reg == BPF_PSEUDO_KFUNC_CALL /* <- new in this patch */ insn->imm == func_btf_id /* btf_id of the running kernel */ [ For the future calling function-in-kernel-module support, an array of module btf_fds can be passed at the load time and insn->off can be used to index into this array. ] At the early stage of verifier, the verifier will collect all kernel function calls into "struct bpf_kfunc_desc". Those descriptors are stored in "prog->aux->kfunc_tab" and will be available to the JIT. Since this "add" operation is similar to the current "add_subprog()" and looking for the same insn->code, they are done together in the new "add_subprog_and_kfunc()". In the "do_check()" stage, the new "check_kfunc_call()" is added to verify the kernel function call instruction: 1. Ensure the kernel function can be used by a particular BPF_PROG_TYPE. A new bpf_verifier_ops "check_kfunc_call" is added to do that. The bpf-tcp-cc struct_ops program will implement this function in a later patch. 2. Call "btf_check_kfunc_args_match()" to ensure the regs can be used as the args of a kernel function. 3. Mark the regs' type, subreg_def, and zext_dst. At the later do_misc_fixups() stage, the new fixup_kfunc_call() will replace the insn->imm with the function address (relative to __bpf_call_base). If needed, the jit can find the btf_func_model by calling the new bpf_jit_find_kfunc_model(prog, insn). With the imm set to the function address, "bpftool prog dump xlated" will be able to display the kernel function calls the same way as it displays other bpf helper calls. gpl_compatible program is required to call kernel function. This feature currently requires JIT. The verifier selftests are adjusted because of the changes in the verbose log in add_subprog_and_kfunc(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015142.1544736-1-kafai@fb.com
2021-03-26bpf: Refactor btf_check_func_arg_matchMartin KaFai Lau
This patch moved the subprog specific logic from btf_check_func_arg_match() to the new btf_check_subprog_arg_match(). The core logic is left in btf_check_func_arg_match() which will be reused later to check the kernel function call. The "if (!btf_type_is_ptr(t))" is checked first to improve the indentation which will be useful for a later patch. Some of the "btf_kind_str[]" usages is replaced with the shortcut "btf_type_str(t)". Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015136.1544504-1-kafai@fb.com
2021-03-26bpf: Simplify freeing logic in linfo and jited_linfoMartin KaFai Lau
This patch simplifies the linfo freeing logic by combining "bpf_prog_free_jited_linfo()" and "bpf_prog_free_unused_jited_linfo()" into the new "bpf_prog_jit_attempt_done()". It is a prep work for the kernel function call support. In a later patch, freeing the kernel function call descriptors will also be done in the "bpf_prog_jit_attempt_done()". "bpf_prog_free_linfo()" is removed since it is only called by "__bpf_prog_put_noref()". The kvfree() are directly called instead. It also takes this chance to s/kcalloc/kvcalloc/ for the jited_linfo allocation. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015130.1544323-1-kafai@fb.com
2021-03-26bpf: Take module reference for trampoline in moduleJiri Olsa
Currently module can be unloaded even if there's a trampoline register in it. It's easily reproduced by running in parallel: # while :; do ./test_progs -t module_attach; done # while :; do rmmod bpf_testmod; sleep 0.5; done Taking the module reference in case the trampoline's ip is within the module code. Releasing it when the trampoline's ip is unregistered. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210326105900.151466-1-jolsa@kernel.org
2021-03-26bpf: Fix a spelling typo in bpf_atomic_alu_string disasmXu Kuohai
The name string for BPF_XOR is "xor", not "or". Fix it. Fixes: 981f94c3e921 ("bpf: Add bitwise atomic instructions") Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Brendan Jackman <jackmanb@google.com> Link: https://lore.kernel.org/bpf/20210325134141.8533-1-xukuohai@huawei.com
2021-03-26bpf: Enforce that struct_ops programs be GPL-onlyToke Høiland-Jørgensen
With the introduction of the struct_ops program type, it became possible to implement kernel functionality in BPF, making it viable to use BPF in place of a regular kernel module for these particular operations. Thus far, the only user of this mechanism is for implementing TCP congestion control algorithms. These are clearly marked as GPL-only when implemented as modules (as seen by the use of EXPORT_SYMBOL_GPL for tcp_register_congestion_control()), so it seems like an oversight that this was not carried over to BPF implementations. Since this is the only user of the struct_ops mechanism, just enforcing GPL-only for the struct_ops program type seems like the simplest way to fix this. Fixes: 0baf26b0fcd7 ("bpf: tcp: Support tcp_congestion_ops in bpf") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210326100314.121853-1-toke@redhat.com
2021-03-25bpf: Add support for batched ops in LPM trie mapsPedro Tammela
Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210323025058.315763-2-pctammela@gmail.com
2021-03-25bpf: Fix NULL pointer dereference in bpf_get_local_storage() helperYonghong Song
Jiri Olsa reported a bug ([1]) in kernel where cgroup local storage pointer may be NULL in bpf_get_local_storage() helper. There are two issues uncovered by this bug: (1). kprobe or tracepoint prog incorrectly sets cgroup local storage before prog run, (2). due to change from preempt_disable to migrate_disable, preemption is possible and percpu storage might be overwritten by other tasks. This issue (1) is fixed in [2]. This patch tried to address issue (2). The following shows how things can go wrong: task 1: bpf_cgroup_storage_set() for percpu local storage preemption happens task 2: bpf_cgroup_storage_set() for percpu local storage preemption happens task 1: run bpf program task 1 will effectively use the percpu local storage setting by task 2 which will be either NULL or incorrect ones. Instead of just one common local storage per cpu, this patch fixed the issue by permitting 8 local storages per cpu and each local storage is identified by a task_struct pointer. This way, we allow at most 8 nested preemption between bpf_cgroup_storage_set() and bpf_cgroup_storage_unset(). The percpu local storage slot is released (calling bpf_cgroup_storage_unset()) by the same task after bpf program finished running. bpf_test_run() is also fixed to use the new bpf_cgroup_storage_set() interface. The patch is tested on top of [2] with reproducer in [1]. Without this patch, kernel will emit error in 2-3 minutes. With this patch, after one hour, still no error. [1] https://lore.kernel.org/bpf/CAKH8qBuXCfUz=w8L+Fj74OaUpbosO29niYwTki7e3Ag044_aww@mail.gmail.com/T [2] https://lore.kernel.org/bpf/20210309185028.3763817-1-yhs@fb.com Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Link: https://lore.kernel.org/bpf/20210323055146.3334476-1-yhs@fb.com
2021-03-26bpf: Undo ptr_to_map_key alu sanitation for nowDaniel Borkmann
Remove PTR_TO_MAP_KEY for the time being from being sanitized on pointer ALU through sanitize_ptr_alu() mainly for 3 reasons: 1) It's currently unused and not available from unprivileged. However that by itself is not yet a strong reason to drop the code. 2) Commit 69c087ba6225 ("bpf: Add bpf_for_each_map_elem() helper") implemented the sanitation not fully correct in that unlike stack or map_value pointer it doesn't probe whether the access to the map key /after/ the simulated ALU operation is still in bounds. This means that the generated mask can truncate the offset in the non-speculative domain whereas it should only truncate in the speculative domain. The verifier should instead reject such program as we do for other types. 3) Given the recent fixes from f232326f6966 ("bpf: Prohibit alu ops for pointer types not defining ptr_limit"), 10d2bb2e6b1d ("bpf: Fix off-by-one for area size in creating mask to left"), b5871dca250c ("bpf: Simplify alu_limit masking for pointer arithmetic") as well as 1b1597e64e1a ("bpf: Add sanity check for upper ptr_limit") the code changed quite a bit and the merge in efd13b71a3fa broke the PTR_TO_MAP_KEY case due to an incorrect merge conflict. Remove the relevant pieces for the time being and we can rework the PTR_TO_MAP_KEY case once everything settles. Fixes: efd13b71a3fa ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net") Fixes: 69c087ba6225 ("bpf: Add bpf_for_each_map_elem() helper") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-03-25Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-03-24 The following pull-request contains BPF updates for your *net-next* tree. We've added 37 non-merge commits during the last 15 day(s) which contain a total of 65 files changed, 3200 insertions(+), 738 deletions(-). The main changes are: 1) Static linking of multiple BPF ELF files, from Andrii. 2) Move drop error path to devmap for XDP_REDIRECT, from Lorenzo. 3) Spelling fixes from various folks. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-24bpf: Avoid old-style declaration warningsArnd Bergmann
gcc -Wextra wants type modifiers in the normal order: kernel/bpf/bpf_lsm.c:70:1: error: 'static' is not at beginning of declaration [-Werror=old-style-declaration] 70 | const static struct bpf_func_proto bpf_bprm_opts_set_proto = { | ^~~~~ kernel/bpf/bpf_lsm.c:91:1: error: 'static' is not at beginning of declaration [-Werror=old-style-declaration] 91 | const static struct bpf_func_proto bpf_ima_inode_hash_proto = { | ^~~~~ Fixes: 3f6719c7b62f ("bpf: Add bpf_bprm_opts_set helper") Fixes: 27672f0d280a ("bpf: Add a BPF helper for getting the IMA hash of an inode") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210322215201.1097281-1-arnd@kernel.org
2021-03-22lsm: separate security_task_getsecid() into subjective and objective variantsPaul Moore
Of the three LSMs that implement the security_task_getsecid() LSM hook, all three LSMs provide the task's objective security credentials. This turns out to be unfortunate as most of the hook's callers seem to expect the task's subjective credentials, although a small handful of callers do correctly expect the objective credentials. This patch is the first step towards fixing the problem: it splits the existing security_task_getsecid() hook into two variants, one for the subjective creds, one for the objective creds. void security_task_getsecid_subj(struct task_struct *p, u32 *secid); void security_task_getsecid_obj(struct task_struct *p, u32 *secid); While this patch does fix all of the callers to use the correct variant, in order to keep this patch focused on the callers and to ease review, the LSMs continue to use the same implementation for both hooks. The net effect is that this patch should not change the behavior of the kernel in any way, it will be up to the latter LSM specific patches in this series to change the hook implementations and return the correct credentials. Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA) Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-03-19bpf: Remove insn_buf[] declaration in inner blockJianlin Lv
Two insn_buf[16] variables are declared in the function which acts on function scope and block scope respectively. The statement in the inner block is redundant, so remove it. Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210318024851.49693-1-Jianlin.Lv@arm.com
2021-03-19bpf: Fix umd memory leak in copy_process()Zqiang
The syzbot reported a memleak as follows: BUG: memory leak unreferenced object 0xffff888101b41d00 (size 120): comm "kworker/u4:0", pid 8, jiffies 4294944270 (age 12.780s) backtrace: [<ffffffff8125dc56>] alloc_pid+0x66/0x560 [<ffffffff81226405>] copy_process+0x1465/0x25e0 [<ffffffff81227943>] kernel_clone+0xf3/0x670 [<ffffffff812281a1>] kernel_thread+0x61/0x80 [<ffffffff81253464>] call_usermodehelper_exec_work [<ffffffff81253464>] call_usermodehelper_exec_work+0xc4/0x120 [<ffffffff812591c9>] process_one_work+0x2c9/0x600 [<ffffffff81259ab9>] worker_thread+0x59/0x5d0 [<ffffffff812611c8>] kthread+0x178/0x1b0 [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 unreferenced object 0xffff888110ef5c00 (size 232): comm "kworker/u4:0", pid 8414, jiffies 4294944270 (age 12.780s) backtrace: [<ffffffff8154a0cf>] kmem_cache_zalloc [<ffffffff8154a0cf>] __alloc_file+0x1f/0xf0 [<ffffffff8154a809>] alloc_empty_file+0x69/0x120 [<ffffffff8154a8f3>] alloc_file+0x33/0x1b0 [<ffffffff8154ab22>] alloc_file_pseudo+0xb2/0x140 [<ffffffff81559218>] create_pipe_files+0x138/0x2e0 [<ffffffff8126c793>] umd_setup+0x33/0x220 [<ffffffff81253574>] call_usermodehelper_exec_async+0xb4/0x1b0 [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 After the UMD process exits, the pipe_to_umh/pipe_from_umh and tgid need to be released. Fixes: d71fa5c9763c ("bpf: Add kernel module with user mode driver that populates bpffs.") Reported-by: syzbot+44908bb56d2bfe56b28e@syzkaller.appspotmail.com Signed-off-by: Zqiang <qiang.zhang@windriver.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210317030915.2865-1-qiang.zhang@windriver.com
2021-03-18bpf, devmap: Move drop error path to devmap for XDP_REDIRECTLorenzo Bianconi
We want to change the current ndo_xdp_xmit drop semantics because it will allow us to implement better queue overflow handling. This is working towards the larger goal of a XDP TX queue-hook. Move XDP_REDIRECT error path handling from each XDP ethernet driver to devmap code. According to the new APIs, the driver running the ndo_xdp_xmit pointer, will break tx loop whenever the hw reports a tx error and it will just return to devmap caller the number of successfully transmitted frames. It will be devmap responsibility to free dropped frames. Move each XDP ndo_xdp_xmit capable driver to the new APIs: - veth - virtio-net - mvneta - mvpp2 - socionext - amazon ena - bnxt - freescale (dpaa2, dpaa) - xen-frontend - qede - ice - igb - ixgbe - i40e - mlx5 - ti (cpsw, cpsw-new) - tun - sfc Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Camelia Groza <camelia.groza@nxp.com> Acked-by: Edward Cree <ecree.xilinx@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Shay Agroskin <shayagr@amazon.com> Link: https://lore.kernel.org/bpf/ed670de24f951cfd77590decf0229a0ad7fd12f6.1615201152.git.lorenzo@kernel.org
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