kernel/linux.git/include/linux/filter.h, branch v5.9.2

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

bpf: Fail PERF_EVENT_IOC_SET_BPF when bpf_get_[stack|stackid] cannot work

2020-07-26T03:16:34+00:00

bpf_get_[stack|stackid] on perf_events with precise_ip uses callchain attached to perf_sample_data. If this callchain is not presented, do not allow attaching BPF program that calls bpf_get_[stack|stackid] to this event. In the error case, -EPROTO is returned so that libbpf can identify this error and print proper hint message. Signed-off-by: Song Liu Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200723180648.1429892-3-songliubraving@fb.com

net: switch copy_bpf_fprog_from_user to sockptr_t

2020-07-24T22:41:53+00:00

Pass a sockptr_t to prepare for set_fs-less handling of the kernel pointer from bpf-cgroup. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2020-07-22T19:35:33+00:00

Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-07-21 The following pull-request contains BPF updates for your *net-next* tree. We've added 46 non-merge commits during the last 6 day(s) which contain a total of 68 files changed, 4929 insertions(+), 526 deletions(-). The main changes are: 1) Run BPF program on socket lookup, from Jakub. 2) Introduce cpumap, from Lorenzo. 3) s390 JIT fixes, from Ilya. 4) teach riscv JIT to emit compressed insns, from Luke. 5) use build time computed BTF ids in bpf iter, from Yonghong. ==================== Purely independent overlapping changes in both filter.h and xdp.h Signed-off-by: David S. Miller

net: simplify cBPF setsockopt compat handling

2020-07-20T01:16:40+00:00

Add a helper that copies either a native or compat bpf_fprog from userspace after verifying the length, and remove the compat setsockopt handlers that now aren't required. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller

inet6: Run SK_LOOKUP BPF program on socket lookup

2020-07-18T03:18:17+00:00

Following ipv4 stack changes, run a BPF program attached to netns before looking up a listening socket. Program can return a listening socket to use as result of socket lookup, fail the lookup, or take no action. Suggested-by: Marek Majkowski Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200717103536.397595-7-jakub@cloudflare.com

inet: Run SK_LOOKUP BPF program on socket lookup

2020-07-18T03:18:16+00:00

Run a BPF program before looking up a listening socket on the receive path. Program selects a listening socket to yield as result of socket lookup by calling bpf_sk_assign() helper and returning SK_PASS code. Program can revert its decision by assigning a NULL socket with bpf_sk_assign(). Alternatively, BPF program can also fail the lookup by returning with SK_DROP, or let the lookup continue as usual with SK_PASS on return, when no socket has been selected with bpf_sk_assign(). This lets the user match packets with listening sockets freely at the last possible point on the receive path, where we know that packets are destined for local delivery after undergoing policing, filtering, and routing. With BPF code selecting the socket, directing packets destined to an IP range or to a port range to a single socket becomes possible. In case multiple programs are attached, they are run in series in the order in which they were attached. The end result is determined from return codes of all the programs according to following rules: 1. If any program returned SK_PASS and selected a valid socket, the socket is used as result of socket lookup. 2. If more than one program returned SK_PASS and selected a socket, last selection takes effect. 3. If any program returned SK_DROP, and no program returned SK_PASS and selected a socket, socket lookup fails with -ECONNREFUSED. 4. If all programs returned SK_PASS and none of them selected a socket, socket lookup continues to htable-based lookup. Suggested-by: Marek Majkowski Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200717103536.397595-5-jakub@cloudflare.com

bpf: Introduce SK_LOOKUP program type with a dedicated attach point

2020-07-18T03:18:16+00:00

Add a new program type BPF_PROG_TYPE_SK_LOOKUP with a dedicated attach type BPF_SK_LOOKUP. The new program kind is to be invoked by the transport layer when looking up a listening socket for a new connection request for connection oriented protocols, or when looking up an unconnected socket for a packet for connection-less protocols. When called, SK_LOOKUP BPF program can select a socket that will receive the packet. This serves as a mechanism to overcome the limits of what bind() API allows to express. Two use-cases driving this work are: (1) steer packets destined to an IP range, on fixed port to a socket 192.0.2.0/24, port 80 -> NGINX socket (2) steer packets destined to an IP address, on any port to a socket 198.51.100.1, any port -> L7 proxy socket In its run-time context program receives information about the packet that triggered the socket lookup. Namely IP version, L4 protocol identifier, and address 4-tuple. Context can be further extended to include ingress interface identifier. To select a socket BPF program fetches it from a map holding socket references, like SOCKMAP or SOCKHASH, and calls bpf_sk_assign(ctx, sk, ...) helper to record the selection. Transport layer then uses the selected socket as a result of socket lookup. In its basic form, SK_LOOKUP acts as a filter and hence must return either SK_PASS or SK_DROP. If the program returns with SK_PASS, transport should look for a socket to receive the packet, or use the one selected by the program if available, while SK_DROP informs the transport layer that the lookup should fail. This patch only enables the user to attach an SK_LOOKUP program to a network namespace. Subsequent patches hook it up to run on local delivery path in ipv4 and ipv6 stacks. Suggested-by: Marek Majkowski Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200717103536.397595-3-jakub@cloudflare.com

bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok()

2020-07-08T23:01:21+00:00

When evaluating access control over kallsyms visibility, credentials at open() time need to be used, not the "current" creds (though in BPF's case, this has likely always been the same). Plumb access to associated file->f_cred down through bpf_dump_raw_ok() and its callers now that kallsysm_show_value() has been refactored to take struct cred. Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: bpf@vger.kernel.org Cc: stable@vger.kernel.org Fixes: 7105e828c087 ("bpf: allow for correlation of maps and helpers in dump") Signed-off-by: Kees Cook

kallsyms: Refactor kallsyms_show_value() to take cred

2020-07-08T22:59:57+00:00

In order to perform future tests against the cred saved during open(), switch kallsyms_show_value() to operate on a cred, and have all current callers pass current_cred(). This makes it very obvious where callers are checking the wrong credential in their "read" contexts. These will be fixed in the coming patches. Additionally switch return value to bool, since it is always used as a direct permission check, not a 0-on-success, negative-on-error style function return. Cc: stable@vger.kernel.org Signed-off-by: Kees Cook