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| author | Linus Torvalds <[email protected]> | 2025-07-30 16:58:50 +0000 |
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| committer | Linus Torvalds <[email protected]> | 2025-07-30 16:58:50 +0000 |
| commit | d9104cec3e8fe4b458b74709853231385779001f (patch) | |
| tree | 1ffc3baa0e963d3301765a5d6cbd5410c8796ee4 /tools/testing/selftests/bpf/progs/mem_rdonly_untrusted.c | |
| parent | Merge tag 'net-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ne... (diff) | |
| parent | Merge branch 'bpf-show-precise-rejected-function-when-attaching-to-__noreturn... (diff) | |
| download | kernel-d9104cec3e8fe4b458b74709853231385779001f.tar.gz kernel-d9104cec3e8fe4b458b74709853231385779001f.zip | |
Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Remove usermode driver (UMD) framework (Thomas Weißschuh)
- Introduce Strongly Connected Component (SCC) in the verifier to
detect loops and refine register liveness (Eduard Zingerman)
- Allow 'void *' cast using bpf_rdonly_cast() and corresponding
'__arg_untrusted' for global function parameters (Eduard Zingerman)
- Improve precision for BPF_ADD and BPF_SUB operations in the verifier
(Harishankar Vishwanathan)
- Teach the verifier that constant pointer to a map cannot be NULL
(Ihor Solodrai)
- Introduce BPF streams for error reporting of various conditions
detected by BPF runtime (Kumar Kartikeya Dwivedi)
- Teach the verifier to insert runtime speculation barrier (lfence on
x86) to mitigate speculative execution instead of rejecting the
programs (Luis Gerhorst)
- Various improvements for 'veristat' (Mykyta Yatsenko)
- For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
improve bug detection by syzbot (Paul Chaignon)
- Support BPF private stack on arm64 (Puranjay Mohan)
- Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
node (Song Liu)
- Introduce kfuncs for read-only string opreations (Viktor Malik)
- Implement show_fdinfo() for bpf_links (Tao Chen)
- Reduce verifier's stack consumption (Yonghong Song)
- Implement mprog API for cgroup-bpf programs (Yonghong Song)
* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
bpf: Add log for attaching tracing programs to functions in deny list
bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
bpf: Fix various typos in verifier.c comments
bpf: Add third round of bounds deduction
selftests/bpf: Test invariants on JSLT crossing sign
selftests/bpf: Test cross-sign 64bits range refinement
selftests/bpf: Update reg_bound range refinement logic
bpf: Improve bounds when s64 crosses sign boundary
bpf: Simplify bounds refinement from s32
selftests/bpf: Enable private stack tests for arm64
bpf, arm64: JIT support for private stack
bpf: Move bpf_jit_get_prog_name() to core.c
bpf, arm64: Fix fp initialization for exception boundary
umd: Remove usermode driver framework
bpf/preload: Don't select USERMODE_DRIVER
selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
selftests/bpf: Increase xdp data size for arm64 64K page size
...
Diffstat (limited to 'tools/testing/selftests/bpf/progs/mem_rdonly_untrusted.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/mem_rdonly_untrusted.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/mem_rdonly_untrusted.c b/tools/testing/selftests/bpf/progs/mem_rdonly_untrusted.c new file mode 100644 index 000000000000..4f94c971ae86 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/mem_rdonly_untrusted.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <vmlinux.h> +#include <bpf/bpf_core_read.h> +#include "bpf_misc.h" +#include "../test_kmods/bpf_testmod_kfunc.h" + +SEC("tp_btf/sys_enter") +__success +__log_level(2) +__msg("r8 = *(u64 *)(r7 +0) ; R7_w=ptr_nameidata(off={{[0-9]+}}) R8_w=rdonly_untrusted_mem(sz=0)") +__msg("r9 = *(u8 *)(r8 +0) ; R8_w=rdonly_untrusted_mem(sz=0) R9_w=scalar") +int btf_id_to_ptr_mem(void *ctx) +{ + struct task_struct *task; + struct nameidata *idata; + u64 ret, off; + + task = bpf_get_current_task_btf(); + idata = task->nameidata; + off = bpf_core_field_offset(struct nameidata, pathname); + /* + * asm block to have reliable match target for __msg, equivalent of: + * ret = task->nameidata->pathname[0]; + */ + asm volatile ( + "r7 = %[idata];" + "r7 += %[off];" + "r8 = *(u64 *)(r7 + 0);" + "r9 = *(u8 *)(r8 + 0);" + "%[ret] = r9;" + : [ret]"=r"(ret) + : [idata]"r"(idata), + [off]"r"(off) + : "r7", "r8", "r9"); + return ret; +} + +SEC("socket") +__success +__retval(0) +int ldx_is_ok_bad_addr(void *ctx) +{ + char *p; + + if (!bpf_core_enum_value_exists(enum bpf_features, BPF_FEAT_RDONLY_CAST_TO_VOID)) + return 42; + + p = bpf_rdonly_cast(0, 0); + return p[0x7fff]; +} + +SEC("socket") +__success +__retval(1) +int ldx_is_ok_good_addr(void *ctx) +{ + int v, *p; + + v = 1; + p = bpf_rdonly_cast(&v, 0); + return *p; +} + +SEC("socket") +__success +int offset_not_tracked(void *ctx) +{ + int *p, i, s; + + p = bpf_rdonly_cast(0, 0); + s = 0; + bpf_for(i, 0, 1000 * 1000 * 1000) { + p++; + s += *p; + } + return s; +} + +SEC("socket") +__failure +__msg("cannot write into rdonly_untrusted_mem") +int stx_not_ok(void *ctx) +{ + int v, *p; + + v = 1; + p = bpf_rdonly_cast(&v, 0); + *p = 1; + return 0; +} + +SEC("socket") +__failure +__msg("cannot write into rdonly_untrusted_mem") +int atomic_not_ok(void *ctx) +{ + int v, *p; + + v = 1; + p = bpf_rdonly_cast(&v, 0); + __sync_fetch_and_add(p, 1); + return 0; +} + +SEC("socket") +__failure +__msg("cannot write into rdonly_untrusted_mem") +int atomic_rmw_not_ok(void *ctx) +{ + long v, *p; + + v = 1; + p = bpf_rdonly_cast(&v, 0); + return __sync_val_compare_and_swap(p, 0, 42); +} + +SEC("socket") +__failure +__msg("invalid access to memory, mem_size=0 off=0 size=4") +__msg("R1 min value is outside of the allowed memory range") +int kfunc_param_not_ok(void *ctx) +{ + int *p; + + p = bpf_rdonly_cast(0, 0); + bpf_kfunc_trusted_num_test(p); + return 0; +} + +SEC("?fentry.s/" SYS_PREFIX "sys_getpgid") +__failure +__msg("R1 type=rdonly_untrusted_mem expected=") +int helper_param_not_ok(void *ctx) +{ + char *p; + + p = bpf_rdonly_cast(0, 0); + /* + * Any helper with ARG_CONST_SIZE_OR_ZERO constraint will do, + * the most permissive constraint + */ + bpf_copy_from_user(p, 0, (void *)42); + return 0; +} + +static __noinline u64 *get_some_addr(void) +{ + if (bpf_get_prandom_u32()) + return bpf_rdonly_cast(0, bpf_core_type_id_kernel(struct sock)); + else + return bpf_rdonly_cast(0, 0); +} + +SEC("socket") +__success +__retval(0) +int mixed_mem_type(void *ctx) +{ + u64 *p; + + /* Try to avoid compiler hoisting load to if branches by using __noinline func. */ + p = get_some_addr(); + return *p; +} + +__attribute__((__aligned__(8))) +u8 global[] = { + 0x11, 0x22, 0x33, 0x44, + 0x55, 0x66, 0x77, 0x88, + 0x99 +}; + +__always_inline +static u64 combine(void *p) +{ + u64 acc; + + acc = 0; +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + acc |= (*(u64 *)p >> 56) << 24; + acc |= (*(u32 *)p >> 24) << 16; + acc |= (*(u16 *)p >> 8) << 8; + acc |= *(u8 *)p; +#else + acc |= (*(u64 *)p & 0xff) << 24; + acc |= (*(u32 *)p & 0xff) << 16; + acc |= (*(u16 *)p & 0xff) << 8; + acc |= *(u8 *)p; +#endif + return acc; +} + +SEC("socket") +__retval(0x88442211) +int diff_size_access(void *ctx) +{ + return combine(bpf_rdonly_cast(&global, 0)); +} + +SEC("socket") +__retval(0x99553322) +int misaligned_access(void *ctx) +{ + return combine(bpf_rdonly_cast(&global, 0) + 1); +} + +__weak int return_one(void) +{ + return 1; +} + +SEC("socket") +__success +__retval(1) +int null_check(void *ctx) +{ + int *p; + + p = bpf_rdonly_cast(0, 0); + if (p == 0) + /* make this a function call to avoid compiler + * moving r0 assignment before check. + */ + return return_one(); + return 0; +} + +char _license[] SEC("license") = "GPL"; |
