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2024-01-25selftests/bpf: Add tests for BPF object load with implicit tokenAndrii Nakryiko1-0/+64
Add a test to validate libbpf's implicit BPF token creation from default BPF FS location (/sys/fs/bpf). Also validate that disabling this implicit BPF token creation works. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-28-andrii@kernel.org
2024-01-25selftests/bpf: Add BPF object loading tests with explicit token passingAndrii Nakryiko3-0/+166
Add a few tests that attempt to load BPF object containing privileged map, program, and the one requiring mandatory BTF uploading into the kernel (to validate token FD propagation to BPF_BTF_LOAD command). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-27-andrii@kernel.org
2024-01-25libbpf: Wire up BPF token support at BPF object levelAndrii Nakryiko4-11/+131
Add BPF token support to BPF object-level functionality. BPF token is supported by BPF object logic either as an explicitly provided BPF token from outside (through BPF FS path), or implicitly (unless prevented through bpf_object_open_opts). Implicit mode is assumed to be the most common one for user namespaced unprivileged workloads. The assumption is that privileged container manager sets up default BPF FS mount point at /sys/fs/bpf with BPF token delegation options (delegate_{cmds,maps,progs,attachs} mount options). BPF object during loading will attempt to create BPF token from /sys/fs/bpf location, and pass it for all relevant operations (currently, map creation, BTF load, and program load). In this implicit mode, if BPF token creation fails due to whatever reason (BPF FS is not mounted, or kernel doesn't support BPF token, etc), this is not considered an error. BPF object loading sequence will proceed with no BPF token. In explicit BPF token mode, user provides explicitly custom BPF FS mount point path. In such case, BPF object will attempt to create BPF token from provided BPF FS location. If BPF token creation fails, that is considered a critical error and BPF object load fails with an error. Libbpf provides a way to disable implicit BPF token creation, if it causes any troubles (BPF token is designed to be completely optional and shouldn't cause any problems even if provided, but in the world of BPF LSM, custom security logic can be installed that might change outcome depending on the presence of BPF token). To disable libbpf's default BPF token creation behavior user should provide either invalid BPF token FD (negative), or empty bpf_token_path option. BPF token presence can influence libbpf's feature probing, so if BPF object has associated BPF token, feature probing is instructed to use BPF object-specific feature detection cache and token FD. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-26-andrii@kernel.org
2024-01-25libbpf: Wire up token_fd into feature probing logicAndrii Nakryiko5-47/+97
Adjust feature probing callbacks to take into account optional token_fd. In unprivileged contexts, some feature detectors would fail to detect kernel support just because BPF program, BPF map, or BTF object can't be loaded due to privileged nature of those operations. So when BPF object is loaded with BPF token, this token should be used for feature probing. This patch is setting support for this scenario, but we don't yet pass non-zero token FD. This will be added in the next patch. We also switched BPF cookie detector from using kprobe program to tracepoint one, as tracepoint is somewhat less dangerous BPF program type and has higher likelihood of being allowed through BPF token in the future. This change has no effect on detection behavior. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-25-andrii@kernel.org
2024-01-25libbpf: Move feature detection code into its own fileAndrii Nakryiko6-466/+481
It's quite a lot of well isolated code, so it seems like a good candidate to move it out of libbpf.c to reduce its size. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-24-andrii@kernel.org
2024-01-25libbpf: Further decouple feature checking logic from bpf_objectAndrii Nakryiko3-11/+22
Add feat_supported() helper that accepts feature cache instead of bpf_object. This allows low-level code in bpf.c to not know or care about higher-level concept of bpf_object, yet it will be able to utilize custom feature checking in cases where BPF token might influence the outcome. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-23-andrii@kernel.org
2024-01-25libbpf: Split feature detectors definitions from cached resultsAndrii Nakryiko1-6/+12
Split a list of supported feature detectors with their corresponding callbacks from actual cached supported/missing values. This will allow to have more flexible per-token or per-object feature detectors in subsequent refactorings. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-22-andrii@kernel.org
2024-01-25selftests/bpf: Utilize string values for delegate_xxx mount optionsAndrii Nakryiko1-20/+32
Use both hex-based and string-based way to specify delegate mount options for BPF FS. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-21-andrii@kernel.org
2024-01-25bpf: Support symbolic BPF FS delegation mount optionsAndrii Nakryiko1-38/+211
Besides already supported special "any" value and hex bit mask, support string-based parsing of delegation masks based on exact enumerator names. Utilize BTF information of `enum bpf_cmd`, `enum bpf_map_type`, `enum bpf_prog_type`, and `enum bpf_attach_type` types to find supported symbolic names (ignoring __MAX_xxx guard values and stripping repetitive prefixes like BPF_ for cmd and attach types, BPF_MAP_TYPE_ for maps, and BPF_PROG_TYPE_ for prog types). The case doesn't matter, but it is normalized to lower case in mount option output. So "PROG_LOAD", "prog_load", and "MAP_create" are all valid values to specify for delegate_cmds options, "array" is among supported for map types, etc. Besides supporting string values, we also support multiple values specified at the same time, using colon (':') separator. There are corresponding changes on bpf_show_options side to use known values to print them in human-readable format, falling back to hex mask printing, if there are any unrecognized bits. This shouldn't be necessary when enum BTF information is present, but in general we should always be able to fall back to this even if kernel was built without BTF. As mentioned, emitted symbolic names are normalized to be all lower case. Example below shows various ways to specify delegate_cmds options through mount command and how mount options are printed back: 12/14 14:39:07.604 vmuser@archvm:~/local/linux/tools/testing/selftests/bpf $ mount | rg token $ sudo mkdir -p /sys/fs/bpf/token $ sudo mount -t bpf bpffs /sys/fs/bpf/token \ -o delegate_cmds=prog_load:MAP_CREATE \ -o delegate_progs=kprobe \ -o delegate_attachs=xdp $ mount | grep token bpffs on /sys/fs/bpf/token type bpf (rw,relatime,delegate_cmds=map_create:prog_load,delegate_progs=kprobe,delegate_attachs=xdp) Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-20-andrii@kernel.org
2024-01-25bpf: Fail BPF_TOKEN_CREATE if no delegation option was set on BPF FSAndrii Nakryiko1-1/+9
It's quite confusing in practice when it's possible to successfully create a BPF token from BPF FS that didn't have any of delegate_xxx mount options set up. While it's not wrong, it's actually more meaningful to reject BPF_TOKEN_CREATE with specific error code (-ENOENT) to let user-space know that no token delegation is setup up. So, instead of creating empty BPF token that will be always ignored because it doesn't have any of the allow_xxx bits set, reject it with -ENOENT. If we ever need empty BPF token to be possible, we can support that with extra flag passed into BPF_TOKEN_CREATE. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-19-andrii@kernel.org
2024-01-25bpf,selinux: Allocate bpf_security_struct per BPF tokenAndrii Nakryiko1-0/+25
Utilize newly added bpf_token_create/bpf_token_free LSM hooks to allocate struct bpf_security_struct for each BPF token object in SELinux. This just follows similar pattern for BPF prog and map. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-18-andrii@kernel.org
2024-01-25selftests/bpf: Add BPF token-enabled testsAndrii Nakryiko1-0/+683
Add a selftest that attempts to conceptually replicate intended BPF token use cases inside user namespaced container. Child process is forked. It is then put into its own userns and mountns. Child creates BPF FS context object. This ensures child userns is captured as the owning userns for this instance of BPF FS. Given setting delegation mount options is privileged operation, we ensure that child cannot set them. This context is passed back to privileged parent process through Unix socket, where parent sets up delegation options, creates, and mounts it as a detached mount. This mount FD is passed back to the child to be used for BPF token creation, which allows otherwise privileged BPF operations to succeed inside userns. We validate that all of token-enabled privileged commands (BPF_BTF_LOAD, BPF_MAP_CREATE, and BPF_PROG_LOAD) work as intended. They should only succeed inside the userns if a) BPF token is provided with proper allowed sets of commands and types; and b) namespaces CAP_BPF and other privileges are set. Lacking a) or b) should lead to -EPERM failures. Based on suggested workflow by Christian Brauner ([0]). [0] https://lore.kernel.org/bpf/20230704-hochverdient-lehne-eeb9eeef785e@brauner/ Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-17-andrii@kernel.org
2024-01-25libbpf: Add BPF token support to bpf_prog_load() APIAndrii Nakryiko2-2/+4
Wire through token_fd into bpf_prog_load(). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-16-andrii@kernel.org
2024-01-25libbpf: Add BPF token support to bpf_btf_load() APIAndrii Nakryiko2-2/+9
Allow user to specify token_fd for bpf_btf_load() API that wraps kernel's BPF_BTF_LOAD command. This allows loading BTF from unprivileged process as long as it has BPF token allowing BPF_BTF_LOAD command, which can be created and delegated by privileged process. Wire through new btf_flags as well, so that user can provide BPF_F_TOKEN_FD flag, if necessary. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-15-andrii@kernel.org
2024-01-25libbpf: Add BPF token support to bpf_map_create() APIAndrii Nakryiko2-4/+7
Add ability to provide token_fd for BPF_MAP_CREATE command through bpf_map_create() API. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-14-andrii@kernel.org
2024-01-25libbpf: Add bpf_token_create() APIAndrii Nakryiko3-0/+42
Add low-level wrapper API for BPF_TOKEN_CREATE command in bpf() syscall. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-13-andrii@kernel.org
2024-01-25bpf,lsm: Add BPF token LSM hooksAndrii Nakryiko6-1/+108
Wire up bpf_token_create and bpf_token_free LSM hooks, which allow to allocate LSM security blob (we add `void *security` field to struct bpf_token for that), but also control who can instantiate BPF token. This follows existing pattern for BPF map and BPF prog. Also add security_bpf_token_allow_cmd() and security_bpf_token_capable() LSM hooks that allow LSM implementation to control and negate (if necessary) BPF token's delegation of a specific bpf_cmd and capability, respectively. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-12-andrii@kernel.org
2024-01-25bpf,lsm: Refactor bpf_map_alloc/bpf_map_free LSM hooksAndrii Nakryiko6-18/+26
Similarly to bpf_prog_alloc LSM hook, rename and extend bpf_map_alloc hook into bpf_map_create, taking not just struct bpf_map, but also bpf_attr and bpf_token, to give a fuller context to LSMs. Unlike bpf_prog_alloc, there is no need to move the hook around, as it currently is firing right before allocating BPF map ID and FD, which seems to be a sweet spot. But like bpf_prog_alloc/bpf_prog_free combo, make sure that bpf_map_free LSM hook is called even if bpf_map_create hook returned error, as if few LSMs are combined together it could be that one LSM successfully allocated security blob for its needs, while subsequent LSM rejected BPF map creation. The former LSM would still need to free up LSM blob, so we need to ensure security_bpf_map_free() is called regardless of the outcome. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-11-andrii@kernel.org
2024-01-25bpf,lsm: Refactor bpf_prog_alloc/bpf_prog_free LSM hooksAndrii Nakryiko6-38/+49
Based on upstream discussion ([0]), rework existing bpf_prog_alloc_security LSM hook. Rename it to bpf_prog_load and instead of passing bpf_prog_aux, pass proper bpf_prog pointer for a full BPF program struct. Also, we pass bpf_attr union with all the user-provided arguments for BPF_PROG_LOAD command. This will give LSMs as much information as we can basically provide. The hook is also BPF token-aware now, and optional bpf_token struct is passed as a third argument. bpf_prog_load LSM hook is called after a bunch of sanity checks were performed, bpf_prog and bpf_prog_aux were allocated and filled out, but right before performing full-fledged BPF verification step. bpf_prog_free LSM hook is now accepting struct bpf_prog argument, for consistency. SELinux code is adjusted to all new names, types, and signatures. Note, given that bpf_prog_load (previously bpf_prog_alloc) hook can be used by some LSMs to allocate extra security blob, but also by other LSMs to reject BPF program loading, we need to make sure that bpf_prog_free LSM hook is called after bpf_prog_load/bpf_prog_alloc one *even* if the hook itself returned error. If we don't do that, we run the risk of leaking memory. This seems to be possible today when combining SELinux and BPF LSM, as one example, depending on their relative ordering. Also, for BPF LSM setup, add bpf_prog_load and bpf_prog_free to sleepable LSM hooks list, as they are both executed in sleepable context. Also drop bpf_prog_load hook from untrusted, as there is no issue with refcount or anything else anymore, that originally forced us to add it to untrusted list in c0c852dd1876 ("bpf: Do not mark certain LSM hook arguments as trusted"). We now trigger this hook much later and it should not be an issue anymore. [0] https://lore.kernel.org/bpf/9fe88aef7deabbe87d3fc38c4aea3c69.paul@paul-moore.com/ Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-10-andrii@kernel.org
2024-01-25bpf: Consistently use BPF token throughout BPF verifier logicAndrii Nakryiko6-20/+19
Remove remaining direct queries to perfmon_capable() and bpf_capable() in BPF verifier logic and instead use BPF token (if available) to make decisions about privileges. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-9-andrii@kernel.org
2024-01-25bpf: Take into account BPF token when fetching helper protosAndrii Nakryiko9-30/+32
Instead of performing unconditional system-wide bpf_capable() and perfmon_capable() calls inside bpf_base_func_proto() function (and other similar ones) to determine eligibility of a given BPF helper for a given program, use previously recorded BPF token during BPF_PROG_LOAD command handling to inform the decision. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-8-andrii@kernel.org
2024-01-25bpf: Add BPF token support to BPF_PROG_LOAD commandAndrii Nakryiko9-27/+118
Add basic support of BPF token to BPF_PROG_LOAD. BPF_F_TOKEN_FD flag should be set in prog_flags field when providing prog_token_fd. Wire through a set of allowed BPF program types and attach types, derived from BPF FS at BPF token creation time. Then make sure we perform bpf_token_capable() checks everywhere where it's relevant. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-7-andrii@kernel.org
2024-01-25bpf: Add BPF token support to BPF_BTF_LOAD commandAndrii Nakryiko3-2/+31
Accept BPF token FD in BPF_BTF_LOAD command to allow BTF data loading through delegated BPF token. BPF_F_TOKEN_FD flag has to be specified when passing BPF token FD. Given BPF_BTF_LOAD command didn't have flags field before, we also add btf_flags field. BTF loading is a pretty straightforward operation, so as long as BPF token is created with allow_cmds granting BPF_BTF_LOAD command, kernel proceeds to parsing BTF data and creating BTF object. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-6-andrii@kernel.org
2024-01-25bpf: Add BPF token support to BPF_MAP_CREATE commandAndrii Nakryiko8-15/+86
Allow providing token_fd for BPF_MAP_CREATE command to allow controlled BPF map creation from unprivileged process through delegated BPF token. New BPF_F_TOKEN_FD flag is added to specify together with BPF token FD for BPF_MAP_CREATE command. Wire through a set of allowed BPF map types to BPF token, derived from BPF FS at BPF token creation time. This, in combination with allowed_cmds allows to create a narrowly-focused BPF token (controlled by privileged agent) with a restrictive set of BPF maps that application can attempt to create. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-5-andrii@kernel.org
2024-01-25bpf: Introduce BPF token objectAndrii Nakryiko7-6/+357
Add new kind of BPF kernel object, BPF token. BPF token is meant to allow delegating privileged BPF functionality, like loading a BPF program or creating a BPF map, from privileged process to a *trusted* unprivileged process, all while having a good amount of control over which privileged operations could be performed using provided BPF token. This is achieved through mounting BPF FS instance with extra delegation mount options, which determine what operations are delegatable, and also constraining it to the owning user namespace (as mentioned in the previous patch). BPF token itself is just a derivative from BPF FS and can be created through a new bpf() syscall command, BPF_TOKEN_CREATE, which accepts BPF FS FD, which can be attained through open() API by opening BPF FS mount point. Currently, BPF token "inherits" delegated command, map types, prog type, and attach type bit sets from BPF FS as is. In the future, having an BPF token as a separate object with its own FD, we can allow to further restrict BPF token's allowable set of things either at the creation time or after the fact, allowing the process to guard itself further from unintentionally trying to load undesired kind of BPF programs. But for now we keep things simple and just copy bit sets as is. When BPF token is created from BPF FS mount, we take reference to the BPF super block's owning user namespace, and then use that namespace for checking all the {CAP_BPF, CAP_PERFMON, CAP_NET_ADMIN, CAP_SYS_ADMIN} capabilities that are normally only checked against init userns (using capable()), but now we check them using ns_capable() instead (if BPF token is provided). See bpf_token_capable() for details. Such setup means that BPF token in itself is not sufficient to grant BPF functionality. User namespaced process has to *also* have necessary combination of capabilities inside that user namespace. So while previously CAP_BPF was useless when granted within user namespace, now it gains a meaning and allows container managers and sys admins to have a flexible control over which processes can and need to use BPF functionality within the user namespace (i.e., container in practice). And BPF FS delegation mount options and derived BPF tokens serve as a per-container "flag" to grant overall ability to use bpf() (plus further restrict on which parts of bpf() syscalls are treated as namespaced). Note also, BPF_TOKEN_CREATE command itself requires ns_capable(CAP_BPF) within the BPF FS owning user namespace, rounding up the ns_capable() story of BPF token. Also creating BPF token in init user namespace is currently not supported, given BPF token doesn't have any effect in init user namespace anyways. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-4-andrii@kernel.org
2024-01-25bpf: Add BPF token delegation mount options to BPF FSAndrii Nakryiko2-12/+90
Add few new mount options to BPF FS that allow to specify that a given BPF FS instance allows creation of BPF token (added in the next patch), and what sort of operations are allowed under BPF token. As such, we get 4 new mount options, each is a bit mask - `delegate_cmds` allow to specify which bpf() syscall commands are allowed with BPF token derived from this BPF FS instance; - if BPF_MAP_CREATE command is allowed, `delegate_maps` specifies a set of allowable BPF map types that could be created with BPF token; - if BPF_PROG_LOAD command is allowed, `delegate_progs` specifies a set of allowable BPF program types that could be loaded with BPF token; - if BPF_PROG_LOAD command is allowed, `delegate_attachs` specifies a set of allowable BPF program attach types that could be loaded with BPF token; delegate_progs and delegate_attachs are meant to be used together, as full BPF program type is, in general, determined through both program type and program attach type. Currently, these mount options accept the following forms of values: - a special value "any", that enables all possible values of a given bit set; - numeric value (decimal or hexadecimal, determined by kernel automatically) that specifies a bit mask value directly; - all the values for a given mount option are combined, if specified multiple times. E.g., `mount -t bpf nodev /path/to/mount -o delegate_maps=0x1 -o delegate_maps=0x2` will result in a combined 0x3 mask. Ideally, more convenient (for humans) symbolic form derived from corresponding UAPI enums would be accepted (e.g., `-o delegate_progs=kprobe|tracepoint`) and I intend to implement this, but it requires a bunch of UAPI header churn, so I postponed it until this feature lands upstream or at least there is a definite consensus that this feature is acceptable and is going to make it, just to minimize amount of wasted effort and not increase amount of non-essential code to be reviewed. Attentive reader will notice that BPF FS is now marked as FS_USERNS_MOUNT, which theoretically makes it mountable inside non-init user namespace as long as the process has sufficient *namespaced* capabilities within that user namespace. But in reality we still restrict BPF FS to be mountable only by processes with CAP_SYS_ADMIN *in init userns* (extra check in bpf_fill_super()). FS_USERNS_MOUNT is added to allow creating BPF FS context object (i.e., fsopen("bpf")) from inside unprivileged process inside non-init userns, to capture that userns as the owning userns. It will still be required to pass this context object back to privileged process to instantiate and mount it. This manipulation is important, because capturing non-init userns as the owning userns of BPF FS instance (super block) allows to use that userns to constraint BPF token to that userns later on (see next patch). So creating BPF FS with delegation inside unprivileged userns will restrict derived BPF token objects to only "work" inside that intended userns, making it scoped to a intended "container". Also, setting these delegation options requires capable(CAP_SYS_ADMIN), so unprivileged process cannot set this up without involvement of a privileged process. There is a set of selftests at the end of the patch set that simulates this sequence of steps and validates that everything works as intended. But careful review is requested to make sure there are no missed gaps in the implementation and testing. This somewhat subtle set of aspects is the result of previous discussions ([0]) about various user namespace implications and interactions with BPF token functionality and is necessary to contain BPF token inside intended user namespace. [0] https://lore.kernel.org/bpf/20230704-hochverdient-lehne-eeb9eeef785e@brauner/ Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-3-andrii@kernel.org
2024-01-25bpf: Align CAP_NET_ADMIN checks with bpf_capable() approachAndrii Nakryiko1-4/+9
Within BPF syscall handling code CAP_NET_ADMIN checks stand out a bit compared to CAP_BPF and CAP_PERFMON checks. For the latter, CAP_BPF or CAP_PERFMON are checked first, but if they are not set, CAP_SYS_ADMIN takes over and grants whatever part of BPF syscall is required. Similar kind of checks that involve CAP_NET_ADMIN are not so consistent. One out of four uses does follow CAP_BPF/CAP_PERFMON model: during BPF_PROG_LOAD, if the type of BPF program is "network-related" either CAP_NET_ADMIN or CAP_SYS_ADMIN is required to proceed. But in three other cases CAP_NET_ADMIN is required even if CAP_SYS_ADMIN is set: - when creating DEVMAP/XDKMAP/CPU_MAP maps; - when attaching CGROUP_SKB programs; - when handling BPF_PROG_QUERY command. This patch is changing the latter three cases to follow BPF_PROG_LOAD model, that is allowing to proceed under either CAP_NET_ADMIN or CAP_SYS_ADMIN. This also makes it cleaner in subsequent BPF token patches to switch wholesomely to a generic bpf_token_capable(int cap) check, that always falls back to CAP_SYS_ADMIN if requested capability is missing. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-2-andrii@kernel.org
2024-01-25libbpf: Ensure undefined bpf_attr field stays 0Martin KaFai Lau1-1/+1
The commit 9e926acda0c2 ("libbpf: Find correct module BTFs for struct_ops maps and progs.") sets a newly added field (value_type_btf_obj_fd) to -1 in libbpf when the caller of the libbpf's bpf_map_create did not define this field by passing a NULL "opts" or passing in a "opts" that does not cover this new field. OPT_HAS(opts, field) is used to decide if the field is defined or not: ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) Once OPTS_HAS decided the field is not defined, that field should be set to 0. For this particular new field (value_type_btf_obj_fd), its corresponding map_flags "BPF_F_VTYPE_BTF_OBJ_FD" is not set. Thus, the kernel does not treat it as an fd field. Fixes: 9e926acda0c2 ("libbpf: Find correct module BTFs for struct_ops maps and progs.") Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240124224418.2905133-1-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-25Merge branch 'fix-module_description-for-net-p2'Jakub Kicinski19-0/+19
Breno Leitao says: ==================== Fix MODULE_DESCRIPTION() for net (p2) There are hundreds of network modules that misses MODULE_DESCRIPTION(), causing a warnning when compiling with W=1. Example: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/arcnet/com90io.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/arcnet/arc-rimi.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/arcnet/com20020.o This part2 of the patchset focus on the drivers/net/ethernet drivers. There are still some missing warnings in drivers/net/ethernet that will be fixed in an upcoming patchset. v1: https://lore.kernel.org/all/20240122184543.2501493-2-leitao@debian.org/ ==================== Link: https://lore.kernel.org/r/20240123190332.677489-1-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for rvu_mboxBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the Marvel RVU mbox driver. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240123190332.677489-11-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for litexBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the LiteX Liteeth Ethernet device. Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Gabriel Somlo <gsomlo@gmail.com> Link: https://lore.kernel.org/r/20240123190332.677489-10-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for fsl_pq_mdioBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the Freescale PQ MDIO driver. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240123190332.677489-9-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for fecBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the FEC (MPC8xx) Ethernet controller. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Wei Fang <wei.fang@nxp.com> Link: https://lore.kernel.org/r/20240123190332.677489-8-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for enetcBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the NXP ENETC Ethernet driver. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240123190332.677489-7-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for nps_enetBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the EZchip NPS ethernet driver. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240123190332.677489-6-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for ep93xxx_ethBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the Cirrus EP93xx ethernet driver. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240123190332.677489-5-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for liquidioBreno Leitao1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the Cavium Liquidio. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240123190332.677489-4-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for Broadcom bgmacBreno Leitao5-0/+5
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the Broadcom iProc GBit driver. Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Florian Fainelli <florian.fainelli@broadcom.com> Link: https://lore.kernel.org/r/20240123190332.677489-3-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25net: fill in MODULE_DESCRIPTION()s for 8390Breno Leitao6-0/+6
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to all the good old 8390 modules and drivers. Signed-off-by: Breno Leitao <leitao@debian.org> CC: geert@linux-m68k.org Link: https://lore.kernel.org/r/20240123190332.677489-2-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25selftests: netdevsim: fix the udp_tunnel_nic testJakub Kicinski1-0/+9
This test is missing a whole bunch of checks for interface renaming and one ifup. Presumably it was only used on a system with renaming disabled and NetworkManager running. Fixes: 91f430b2c49d ("selftests: net: add a test for UDP tunnel info infra") Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240123060529.1033912-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25selftests: net: fix rps_default_mask with >32 CPUsJakub Kicinski1-1/+5
If there is more than 32 cpus the bitmask will start to contain commas, leading to: ./rps_default_mask.sh: line 36: [: 00000000,00000000: integer expression expected Remove the commas, bash doesn't interpret leading zeroes as oct so that should be good enough. Switch to bash, Simon reports that not all shells support this type of substitution. Fixes: c12e0d5f267d ("self-tests: introduce self-tests for RPS default mask") Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240122195815.638997-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-25Merge tag 'execve-v6.8-rc2' of ↵Linus Torvalds4-11/+34
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull execve fixes from Kees Cook: - Fix error handling in begin_new_exec() (Bernd Edlinger) - MAINTAINERS: specifically mention ELF (Alexey Dobriyan) - Various cleanups related to earlier open() (Askar Safin, Kees Cook) * tag 'execve-v6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: exec: Distinguish in_execve from in_exec exec: Fix error handling in begin_new_exec() exec: Add do_close_execat() helper exec: remove useless comment ELF, MAINTAINERS: specifically mention ELF
2024-01-25uselib: remove use of __FMODE_EXECLinus Torvalds1-1/+1
Jann Horn points out that uselib() really shouldn't trigger the new FMODE_EXEC logic introduced by commit 4759ff71f23e ("exec: __FMODE_EXEC instead of in_execve for LSMs"). In fact, it shouldn't even have ever triggered the old pre-existing logic for __FMODE_EXEC (like the NFS code that makes executables not need read permissions). Unlike a real execve(), that can work even with files that are purely executable by the user (not readable), uselib() has that MAY_READ requirement becasue it's really just a convenience wrapper around mmap() for legacy shared libraries. The whole FMODE_EXEC bit was originally introduced by commit b500531e6f5f ("[PATCH] Introduce FMODE_EXEC file flag"), primarily to give ETXTBUSY error returns for distributed filesystems. It has since grown a few other warts (like that NFS thing), but there really isn't any reason to use it for uselib(), and now that we are trying to use it to replace the horrid 'tsk->in_execve' flag, it's actively wrong. Of course, as Jann Horn also points out, nobody should be enabling CONFIG_USELIB in the first place in this day and age, but that's a different discussion entirely. Reported-by: Jann Horn <jannh@google.com> Fixes: 4759ff71f23e ("exec: __FMODE_EXEC instead of in_execve for LSMs") Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-01-25Revert "KEYS: encrypted: Add check for strsep"Mimi Zohar1-4/+0
This reverts commit b4af096b5df5dd131ab796c79cedc7069d8f4882. New encrypted keys are created either from kernel-generated random numbers or user-provided decrypted data. Revert the change requiring user-provided decrypted data. Reported-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2024-01-24net: mvpp2: clear BM pool before initializationJenishkumar Maheshbhai Patel1-1/+26
Register value persist after booting the kernel using kexec which results in kernel panic. Thus clear the BM pool registers before initialisation to fix the issue. Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit") Signed-off-by: Jenishkumar Maheshbhai Patel <jpatel2@marvell.com> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Link: https://lore.kernel.org/r/20240119035914.2595665-1-jpatel2@marvell.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-24net: stmmac: Wait a bit for the reset to take effectBernd Edlinger1-0/+3
otherwise the synopsys_id value may be read out wrong, because the GMAC_VERSION register might still be in reset state, for at least 1 us after the reset is de-asserted. Add a wait for 10 us before continuing to be on the safe side. > From what have you got that delay value? Just try and error, with very old linux versions and old gcc versions the synopsys_id was read out correctly most of the time (but not always), with recent linux versions and recnet gcc versions it was read out wrongly most of the time, but again not always. I don't have access to the VHDL code in question, so I cannot tell why it takes so long to get the correct values, I also do not have more than a few hardware samples, so I cannot tell how long this timeout must be in worst case. Experimentally I can tell that the register is read several times as zero immediately after the reset is de-asserted, also adding several no-ops is not enough, adding a printk is enough, also udelay(1) seems to be enough but I tried that not very often, and I have not access to many hardware samples to be 100% sure about the necessary delay. And since the udelay here is only executed once per device instance, it seems acceptable to delay the boot for 10 us. BTW: my hardware's synopsys id is 0x37. Fixes: c5e4ddbdfa11 ("net: stmmac: Add support for optional reset control") Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Link: https://lore.kernel.org/r/AS8P193MB1285A810BD78C111E7F6AA34E4752@AS8P193MB1285.EURP193.PROD.OUTLOOK.COM Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-24samples/cgroup: add .gitignore file for generated samplesLinus Torvalds1-0/+3
Make 'git status' quietly happy again after a full allmodconfig build. Fixes: 60433a9d038d ("samples: introduce new samples subdir for cgroup") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-01-24exec: Distinguish in_execve from in_execKees Cook3-1/+3
Just to help distinguish the fs->in_exec flag from the current->in_execve flag, add comments in check_unsafe_exec() and copy_fs() for more context. Also note that in_execve is only used by TOMOYO now. Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Kees Cook <keescook@chromium.org>
2024-01-24exec: Check __FMODE_EXEC instead of in_execve for LSMsKees Cook2-2/+5
After commit 978ffcbf00d8 ("execve: open the executable file before doing anything else"), current->in_execve was no longer in sync with the open(). This broke AppArmor and TOMOYO which depend on this flag to distinguish "open" operations from being "exec" operations. Instead of moving around in_execve, switch to using __FMODE_EXEC, which is where the "is this an exec?" intent is stored. Note that TOMOYO still uses in_execve around cred handling. Reported-by: Kevin Locke <kevin@kevinlocke.name> Closes: https://lore.kernel.org/all/ZbE4qn9_h14OqADK@kevinlocke.name Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Fixes: 978ffcbf00d8 ("execve: open the executable file before doing anything else") Cc: Josh Triplett <josh@joshtriplett.org> Cc: John Johansen <john.johansen@canonical.com> Cc: Paul Moore <paul@paul-moore.com> Cc: James Morris <jmorris@namei.org> Cc: Serge E. Hallyn <serge@hallyn.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: <linux-fsdevel@vger.kernel.org> Cc: <linux-mm@kvack.org> Cc: <apparmor@lists.ubuntu.com> Cc: <linux-security-module@vger.kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-01-24netfilter: nf_tables: validate NFPROTO_* familyPablo Neira Ayuso8-2/+47
Several expressions explicitly refer to NF_INET_* hook definitions from expr->ops->validate, however, family is not validated. Bail out with EOPNOTSUPP in case they are used from unsupported families. Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables") Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression") Fixes: 2fa841938c64 ("netfilter: nf_tables: introduce routing expression") Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching") Fixes: ad49d86e07a4 ("netfilter: nf_tables: Add synproxy support") Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support") Fixes: 6c47260250fc ("netfilter: nf_tables: add xfrm expression") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
generated by cgit v1.2.3 (git 2.39.0) at 2025-10-02 10:22:30 +0300