pm24.git/kernel/bpf, branch rust-fixes-6.12

Merge tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-09-24T21:54:26Z

Pull bpf 'struct fd' updates from Alexei Starovoitov: "This includes struct_fd BPF changes from Al and Andrii" * tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: bpf: convert bpf_token_create() to CLASS(fd, ...) security,bpf: constify struct path in bpf_token_create() LSM hook bpf: more trivial fdget() conversions bpf: trivial conversions for fdget() bpf: switch maps to CLASS(fd, ...) bpf: factor out fetching bpf_map from FD and adding it to used_maps list bpf: switch fdget_raw() uses to CLASS(fd_raw, ...) bpf: convert __bpf_prog_get() to CLASS(fd, ...)

Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-09-23T16:35:36Z

Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.

Merge tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-09-21T16:27:50Z

Pull bpf updates from Alexei Starovoitov: - Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with corresponding support in LLVM. It is similar to existing 'no_caller_saved_registers' attribute in GCC/LLVM with a provision for backward compatibility. It allows compilers generate more efficient BPF code assuming the verifier or JITs will inline or partially inline a helper/kfunc with such attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast, bpf_get_smp_processor_id are the first set of such helpers. - Harden and extend ELF build ID parsing logic. When called from sleepable context the relevants parts of ELF file will be read to find and fetch .note.gnu.build-id information. Also harden the logic to avoid TOCTOU, overflow, out-of-bounds problems. - Improvements and fixes for sched-ext: - Allow passing BPF iterators as kfunc arguments - Make the pointer returned from iter_next method trusted - Fix x86 JIT convergence issue due to growing/shrinking conditional jumps in variable length encoding - BPF_LSM related: - Introduce few VFS kfuncs and consolidate them in fs/bpf_fs_kfuncs.c - Enforce correct range of return values from certain LSM hooks - Disallow attaching to other LSM hooks - Prerequisite work for upcoming Qdisc in BPF: - Allow kptrs in program provided structs - Support for gen_epilogue in verifier_ops - Important fixes: - Fix uprobe multi pid filter check - Fix bpf_strtol and bpf_strtoul helpers - Track equal scalars history on per-instruction level - Fix tailcall hierarchy on x86 and arm64 - Fix signed division overflow to prevent INT_MIN/-1 trap on x86 - Fix get kernel stack in BPF progs attached to tracepoint:syscall - Selftests: - Add uprobe bench/stress tool - Generate file dependencies to drastically improve re-build time - Match JIT-ed and BPF asm with __xlated/__jited keywords - Convert older tests to test_progs framework - Add support for RISC-V - Few fixes when BPF programs are compiled with GCC-BPF backend (support for GCC-BPF in BPF CI is ongoing in parallel) - Add traffic monitor - Enable cross compile and musl libc * tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits) btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh bpf: Call the missed kfree() when there is no special field in btf bpf: Call the missed btf_record_free() when map creation fails selftests/bpf: Add a test case to write mtu result into .rodata selftests/bpf: Add a test case to write strtol result into .rodata selftests/bpf: Rename ARG_PTR_TO_LONG test description selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types bpf: Fix helper writes to read-only maps bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit selftests/bpf: Add tests for sdiv/smod overflow cases bpf: Fix a sdiv overflow issue libbpf: Add bpf_object__token_fd accessor docs/bpf: Add missing BPF program types to docs docs/bpf: Add constant values for linkages bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing ...

bpf: Call the missed kfree() when there is no special field in btf

2024-09-13T23:51:08Z

Call the missed kfree() in btf_parse_struct_metas() when there is no special field in btf, otherwise will get the following kmemleak report: unreferenced object 0xffff888101033620 (size 8): comm "test_progs", pid 604, jiffies 4295127011 ...... backtrace (crc e77dc444): [<00000000186f90f3>] kmemleak_alloc+0x4b/0x80 [<00000000ac8e9c4d>] __kmalloc_cache_noprof+0x2a1/0x310 [<00000000d99d68d6>] btf_new_fd+0x72d/0xe90 [<00000000f010b7f8>] __sys_bpf+0xec3/0x2410 [<00000000e077ed6f>] __x64_sys_bpf+0x1f/0x30 [<00000000a12f9e55>] x64_sys_call+0x199/0x9f0 [<00000000f3029ea6>] do_syscall_64+0x3b/0xc0 [<000000005640913a>] entry_SYSCALL_64_after_hwframe+0x4b/0x53 Fixes: 7a851ecb1806 ("bpf: Search for kptrs in prog BTF structs") Signed-off-by: Hou Tao Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20240912012845.3458483-3-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov

bpf: Call the missed btf_record_free() when map creation fails

2024-09-13T23:51:08Z

When security_bpf_map_create() in map_create() fails, map_create() will call btf_put() and ->map_free() callback to free the map. It doesn't free the btf_record of map value, so add the missed btf_record_free() when map creation fails. However btf_record_free() needs to be called after ->map_free() just like bpf_map_free_deferred() did, because ->map_free() may use the btf_record to free the special fields in preallocated map value. So factor out bpf_map_free() helper to free the map, btf_record, and btf orderly and use the helper in both map_create() and bpf_map_free_deferred(). Signed-off-by: Hou Tao Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20240912012845.3458483-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov

bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error

2024-09-13T20:17:56Z

For all non-tracing helpers which formerly had ARG_PTR_TO_{LONG,INT} as input arguments, zero the value for the case of an error as otherwise it could leak memory. For tracing, it is not needed given CAP_PERFMON can already read all kernel memory anyway hence bpf_get_func_arg() and bpf_get_func_ret() is skipped in here. Also, the MTU helpers mtu_len pointer value is being written but also read. Technically, the MEM_UNINIT should not be there in order to always force init. Removing MEM_UNINIT needs more verifier rework though: MEM_UNINIT right now implies two things actually: i) write into memory, ii) memory does not have to be initialized. If we lift MEM_UNINIT, it then becomes: i) read into memory, ii) memory must be initialized. This means that for bpf_*_check_mtu() we're readding the issue we're trying to fix, that is, it would then be able to write back into things like .rodata BPF maps. Follow-up work will rework the MEM_UNINIT semantics such that the intent can be better expressed. For now just clear the *mtu_len on error path which can be lifted later again. Fixes: 8a67f2de9b1d ("bpf: expose bpf_strtol and bpf_strtoul to all program types") Fixes: d7a4cb9b6705 ("bpf: Introduce bpf_strtol and bpf_strtoul helpers") Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/e5edd241-59e7-5e39-0ee5-a51e31b6840a@iogearbox.net Link: https://lore.kernel.org/r/20240913191754.13290-5-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov

bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types

2024-09-13T20:17:56Z

When checking malformed helper function signatures, also take other argument types into account aside from just ARG_PTR_TO_UNINIT_MEM. This concerns (formerly) ARG_PTR_TO_{INT,LONG} given uninitialized memory can be passed there, too. The func proto sanity check goes back to commit 435faee1aae9 ("bpf, verifier: add ARG_PTR_TO_RAW_STACK type"), and its purpose was to detect wrong func protos which had more than just one MEM_UNINIT-tagged type as arguments. The reason more than one is currently not supported is as we mark stack slots with STACK_MISC in check_helper_call() in case of raw mode based on meta.access_size to allow uninitialized stack memory to be passed to helpers when they just write into the buffer. Probing for base type as well as MEM_UNINIT tagging ensures that other types do not get missed (as it used to be the case for ARG_PTR_TO_{INT,LONG}). Fixes: 57c3bb725a3d ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types") Reported-by: Shung-Hsi Yu Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Acked-by: Shung-Hsi Yu Link: https://lore.kernel.org/r/20240913191754.13290-4-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov

bpf: Fix helper writes to read-only maps

2024-09-13T20:17:55Z

Lonial found an issue that despite user- and BPF-side frozen BPF map (like in case of .rodata), it was still possible to write into it from a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT} as arguments. In check_func_arg() when the argument is as mentioned, the meta->raw_mode is never set. Later, check_helper_mem_access(), under the case of PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the subsequent call to check_map_access_type() and given the BPF map is read-only it succeeds. The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT when results are written into them as opposed to read out of them. The latter indicates that it's okay to pass a pointer to uninitialized memory as the memory is written to anyway. However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM just with additional alignment requirement. So it is better to just get rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the fixed size memory types. For this, add MEM_ALIGNED to additionally ensure alignment given these helpers write directly into the args via * = val. The .arg*_size has been initialized reflecting the actual sizeof(*). MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated argument types, since in !MEM_FIXED_SIZE cases the verifier does not know the buffer size a priori and therefore cannot blindly write * = val. Fixes: 57c3bb725a3d ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types") Reported-by: Lonial Con Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Acked-by: Shung-Hsi Yu Link: https://lore.kernel.org/r/20240913191754.13290-3-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov

bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers

2024-09-13T20:17:55Z

Both bpf_strtol() and bpf_strtoul() helpers passed a temporary "long long" respectively "unsigned long long" to __bpf_strtoll() / __bpf_strtoull(). Later, the result was checked for truncation via _res != ({unsigned,} long)_res as the destination buffer for the BPF helpers was of type {unsigned,} long which is 32bit on 32bit architectures. Given the latter was a bug in the helper signatures where the destination buffer got adjusted to {s,u}64, the truncation check can now be removed. Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20240913191754.13290-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov

bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit

2024-09-13T20:17:55Z

The bpf_strtol() and bpf_strtoul() helpers are currently broken on 32bit: The argument type ARG_PTR_TO_LONG is BPF-side "long", not kernel-side "long" and therefore always considered fixed 64bit no matter if 64 or 32bit underlying architecture. This contract breaks in case of the two mentioned helpers since their BPF_CALL definition for the helpers was added with {unsigned,}long *res. Meaning, the transition from BPF-side "long" (BPF program) to kernel-side "long" (BPF helper) breaks here. Both helpers call __bpf_strtoll() with "long long" correctly, but later assigning the result into 32-bit "*(long *)" on 32bit architectures. From a BPF program point of view, this means upper bits will be seen as uninitialised. Therefore, fix both BPF_CALL signatures to {s,u}64 types to fix this situation. Now, changing also uapi/bpf.h helper documentation which generates bpf_helper_defs.h for BPF programs is tricky: Changing signatures there to __{s,u}64 would trigger compiler warnings (incompatible pointer types passing 'long *' to parameter of type '__s64 *' (aka 'long long *')) for existing BPF programs. Leaving the signatures as-is would be fine as from BPF program point of view it is still BPF-side "long" and thus equivalent to __{s,u}64 on 64 or 32bit underlying architectures. Note that bpf_strtol() and bpf_strtoul() are the only helpers with this issue. Fixes: d7a4cb9b6705 ("bpf: Introduce bpf_strtol and bpf_strtoul helpers") Reported-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/481fcec8-c12c-9abb-8ecb-76c71c009959@iogearbox.net Link: https://lore.kernel.org/r/20240913191754.13290-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov