diff options
Diffstat (limited to 'tools/testing')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/stack_var_off.c | 35 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_stack_var_off.c | 51 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/basic_stack.c | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/calls.c | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/const_or.c | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/helper_access_var_len.c | 12 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/int_ptr.c | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/raw_stack.c | 10 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/stack_ptr.c | 22 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/unpriv.c | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/var_off.c | 115 |
11 files changed, 224 insertions, 39 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/stack_var_off.c b/tools/testing/selftests/bpf/prog_tests/stack_var_off.c new file mode 100644 index 000000000000..2ce9deefa59c --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/stack_var_off.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include "test_stack_var_off.skel.h" + +/* Test read and writes to the stack performed with offsets that are not + * statically known. + */ +void test_stack_var_off(void) +{ + int duration = 0; + struct test_stack_var_off *skel; + + skel = test_stack_var_off__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + + /* Give pid to bpf prog so it doesn't trigger for anyone else. */ + skel->bss->test_pid = getpid(); + /* Initialize the probe's input. */ + skel->bss->input[0] = 2; + skel->bss->input[1] = 42; /* This will be returned in probe_res. */ + + if (!ASSERT_OK(test_stack_var_off__attach(skel), "skel_attach")) + goto cleanup; + + /* Trigger probe. */ + usleep(1); + + if (CHECK(skel->bss->probe_res != 42, "check_probe_res", + "wrong probe res: %d\n", skel->bss->probe_res)) + goto cleanup; + +cleanup: + test_stack_var_off__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_stack_var_off.c b/tools/testing/selftests/bpf/progs/test_stack_var_off.c new file mode 100644 index 000000000000..665e6ae09d37 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_stack_var_off.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +int probe_res; + +char input[4] = {}; +int test_pid; + +SEC("tracepoint/syscalls/sys_enter_nanosleep") +int probe(void *ctx) +{ + /* This BPF program performs variable-offset reads and writes on a + * stack-allocated buffer. + */ + char stack_buf[16]; + unsigned long len; + unsigned long last; + + if ((bpf_get_current_pid_tgid() >> 32) != test_pid) + return 0; + + /* Copy the input to the stack. */ + __builtin_memcpy(stack_buf, input, 4); + + /* The first byte in the buffer indicates the length. */ + len = stack_buf[0] & 0xf; + last = (len - 1) & 0xf; + + /* Append something to the buffer. The offset where we write is not + * statically known; this is a variable-offset stack write. + */ + stack_buf[len] = 42; + + /* Index into the buffer at an unknown offset. This is a + * variable-offset stack read. + * + * Note that if it wasn't for the preceding variable-offset write, this + * read would be rejected because the stack slot cannot be verified as + * being initialized. With the preceding variable-offset write, the + * stack slot still cannot be verified, but the write inhibits the + * respective check on the reasoning that, if there was a + * variable-offset to a higher-or-equal spot, we're probably reading + * what we just wrote. + */ + probe_res = stack_buf[last]; + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/verifier/basic_stack.c b/tools/testing/selftests/bpf/verifier/basic_stack.c index b56f8117c09d..f995777dddb3 100644 --- a/tools/testing/selftests/bpf/verifier/basic_stack.c +++ b/tools/testing/selftests/bpf/verifier/basic_stack.c @@ -4,7 +4,7 @@ BPF_ST_MEM(BPF_DW, BPF_REG_10, 8, 0), BPF_EXIT_INSN(), }, - .errstr = "invalid stack", + .errstr = "invalid write to stack", .result = REJECT, }, { diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index c4f5d909e58a..eb888c8479c3 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -1228,7 +1228,7 @@ .prog_type = BPF_PROG_TYPE_XDP, .fixup_map_hash_8b = { 23 }, .result = REJECT, - .errstr = "invalid read from stack off -16+0 size 8", + .errstr = "invalid read from stack R7 off=-16 size=8", }, { "calls: two calls that receive map_value via arg=ptr_stack_of_caller. test1", @@ -1958,7 +1958,7 @@ BPF_EXIT_INSN(), }, .fixup_map_hash_48b = { 6 }, - .errstr = "invalid indirect read from stack off -8+0 size 8", + .errstr = "invalid indirect read from stack R2 off -8+0 size 8", .result = REJECT, .prog_type = BPF_PROG_TYPE_XDP, }, diff --git a/tools/testing/selftests/bpf/verifier/const_or.c b/tools/testing/selftests/bpf/verifier/const_or.c index 6c214c58e8d4..0719b0ddec04 100644 --- a/tools/testing/selftests/bpf/verifier/const_or.c +++ b/tools/testing/selftests/bpf/verifier/const_or.c @@ -23,7 +23,7 @@ BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel), BPF_EXIT_INSN(), }, - .errstr = "invalid stack type R1 off=-48 access_size=58", + .errstr = "invalid indirect access to stack R1 off=-48 size=58", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, @@ -54,7 +54,7 @@ BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel), BPF_EXIT_INSN(), }, - .errstr = "invalid stack type R1 off=-48 access_size=58", + .errstr = "invalid indirect access to stack R1 off=-48 size=58", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, diff --git a/tools/testing/selftests/bpf/verifier/helper_access_var_len.c b/tools/testing/selftests/bpf/verifier/helper_access_var_len.c index 87c4e7900083..0ab7f1dfc97a 100644 --- a/tools/testing/selftests/bpf/verifier/helper_access_var_len.c +++ b/tools/testing/selftests/bpf/verifier/helper_access_var_len.c @@ -39,7 +39,7 @@ BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel), BPF_EXIT_INSN(), }, - .errstr = "invalid indirect read from stack off -64+0 size 64", + .errstr = "invalid indirect read from stack R1 off -64+0 size 64", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, @@ -59,7 +59,7 @@ BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "invalid stack type R1 off=-64 access_size=65", + .errstr = "invalid indirect access to stack R1 off=-64 size=65", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, @@ -136,7 +136,7 @@ BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "invalid stack type R1 off=-64 access_size=65", + .errstr = "invalid indirect access to stack R1 off=-64 size=65", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, @@ -156,7 +156,7 @@ BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "invalid stack type R1 off=-64 access_size=65", + .errstr = "invalid indirect access to stack R1 off=-64 size=65", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, @@ -194,7 +194,7 @@ BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "invalid indirect read from stack off -64+0 size 64", + .errstr = "invalid indirect read from stack R1 off -64+0 size 64", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, @@ -584,7 +584,7 @@ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16), BPF_EXIT_INSN(), }, - .errstr = "invalid indirect read from stack off -64+32 size 64", + .errstr = "invalid indirect read from stack R1 off -64+32 size 64", .result = REJECT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, diff --git a/tools/testing/selftests/bpf/verifier/int_ptr.c b/tools/testing/selftests/bpf/verifier/int_ptr.c index ca3b4729df66..070893fb2900 100644 --- a/tools/testing/selftests/bpf/verifier/int_ptr.c +++ b/tools/testing/selftests/bpf/verifier/int_ptr.c @@ -27,7 +27,7 @@ }, .result = REJECT, .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL, - .errstr = "invalid indirect read from stack off -16+0 size 8", + .errstr = "invalid indirect read from stack R4 off -16+0 size 8", }, { "ARG_PTR_TO_LONG half-uninitialized", @@ -59,7 +59,7 @@ }, .result = REJECT, .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL, - .errstr = "invalid indirect read from stack off -16+4 size 8", + .errstr = "invalid indirect read from stack R4 off -16+4 size 8", }, { "ARG_PTR_TO_LONG misaligned", @@ -125,7 +125,7 @@ }, .result = REJECT, .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL, - .errstr = "invalid stack type R4 off=-4 access_size=8", + .errstr = "invalid indirect access to stack R4 off=-4 size=8", }, { "ARG_PTR_TO_LONG initialized", diff --git a/tools/testing/selftests/bpf/verifier/raw_stack.c b/tools/testing/selftests/bpf/verifier/raw_stack.c index 193d9e87d5a9..cc8e8c3cdc03 100644 --- a/tools/testing/selftests/bpf/verifier/raw_stack.c +++ b/tools/testing/selftests/bpf/verifier/raw_stack.c @@ -11,7 +11,7 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid read from stack off -8+0 size 8", + .errstr = "invalid read from stack R6 off=-8 size=8", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, { @@ -59,7 +59,7 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack type R3", + .errstr = "invalid zero-sized read", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, { @@ -205,7 +205,7 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack type R3 off=-513 access_size=8", + .errstr = "invalid indirect access to stack R3 off=-513 size=8", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, { @@ -221,7 +221,7 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack type R3 off=-1 access_size=8", + .errstr = "invalid indirect access to stack R3 off=-1 size=8", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, { @@ -285,7 +285,7 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack type R3 off=-512 access_size=0", + .errstr = "invalid zero-sized read", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, { diff --git a/tools/testing/selftests/bpf/verifier/stack_ptr.c b/tools/testing/selftests/bpf/verifier/stack_ptr.c index 8bfeb77c60bd..07eaa04412ae 100644 --- a/tools/testing/selftests/bpf/verifier/stack_ptr.c +++ b/tools/testing/selftests/bpf/verifier/stack_ptr.c @@ -44,7 +44,7 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack off=-79992 size=8", + .errstr = "invalid write to stack R1 off=-79992 size=8", .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", }, { @@ -57,7 +57,7 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack off=0 size=8", + .errstr = "invalid write to stack R1 off=0 size=8", }, { "PTR_TO_STACK check high 1", @@ -106,7 +106,7 @@ BPF_EXIT_INSN(), }, .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", - .errstr = "invalid stack off=0 size=1", + .errstr = "invalid write to stack R1 off=0 size=1", .result = REJECT, }, { @@ -119,7 +119,8 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack off", + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .errstr = "invalid write to stack R1", }, { "PTR_TO_STACK check high 6", @@ -131,7 +132,8 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack off", + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .errstr = "invalid write to stack", }, { "PTR_TO_STACK check high 7", @@ -183,7 +185,7 @@ BPF_EXIT_INSN(), }, .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", - .errstr = "invalid stack off=-513 size=1", + .errstr = "invalid write to stack R1 off=-513 size=1", .result = REJECT, }, { @@ -208,7 +210,8 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack off", + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .errstr = "invalid write to stack", }, { "PTR_TO_STACK check low 6", @@ -220,7 +223,8 @@ BPF_EXIT_INSN(), }, .result = REJECT, - .errstr = "invalid stack off", + .errstr = "invalid write to stack", + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", }, { "PTR_TO_STACK check low 7", @@ -292,7 +296,7 @@ BPF_EXIT_INSN(), }, .result_unpriv = REJECT, - .errstr_unpriv = "invalid stack off=0 size=1", + .errstr_unpriv = "invalid write to stack R1 off=0 size=1", .result = ACCEPT, .retval = 42, }, diff --git a/tools/testing/selftests/bpf/verifier/unpriv.c b/tools/testing/selftests/bpf/verifier/unpriv.c index ee298627abae..b018ad71e0a8 100644 --- a/tools/testing/selftests/bpf/verifier/unpriv.c +++ b/tools/testing/selftests/bpf/verifier/unpriv.c @@ -108,7 +108,7 @@ BPF_EXIT_INSN(), }, .fixup_map_hash_8b = { 3 }, - .errstr_unpriv = "invalid indirect read from stack off -8+0 size 8", + .errstr_unpriv = "invalid indirect read from stack R2 off -8+0 size 8", .result_unpriv = REJECT, .result = ACCEPT, }, diff --git a/tools/testing/selftests/bpf/verifier/var_off.c b/tools/testing/selftests/bpf/verifier/var_off.c index 8504ac937809..eab1f7f56e2f 100644 --- a/tools/testing/selftests/bpf/verifier/var_off.c +++ b/tools/testing/selftests/bpf/verifier/var_off.c @@ -18,7 +18,7 @@ .prog_type = BPF_PROG_TYPE_LWT_IN, }, { - "variable-offset stack access", + "variable-offset stack read, priv vs unpriv", .insns = { /* Fill the top 8 bytes of the stack */ BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), @@ -31,15 +31,110 @@ * we don't know which */ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10), - /* dereference it */ + /* dereference it for a stack read */ + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R2 variable stack access prohibited for !root", + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, +}, +{ + "variable-offset stack read, uninitialized", + .insns = { + /* Get an unknown value */ + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0), + /* Make it small and 4-byte aligned */ + BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4), + BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 8), + /* add it to fp. We now have either fp-4 or fp-8, but + * we don't know which + */ + BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10), + /* dereference it for a stack read */ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "variable stack access var_off=(0xfffffffffffffff8; 0x4)", .result = REJECT, + .errstr = "invalid variable-offset read from stack R2", .prog_type = BPF_PROG_TYPE_LWT_IN, }, { + "variable-offset stack write, priv vs unpriv", + .insns = { + /* Get an unknown value */ + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0), + /* Make it small and 8-byte aligned */ + BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 8), + BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16), + /* Add it to fp. We now have either fp-8 or fp-16, but + * we don't know which + */ + BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10), + /* Dereference it for a stack write */ + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + /* Now read from the address we just wrote. This shows + * that, after a variable-offset write, a priviledged + * program can read the slots that were in the range of + * that write (even if the verifier doesn't actually know + * if the slot being read was really written to or not. + */ + BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + /* Variable stack access is rejected for unprivileged. + */ + .errstr_unpriv = "R2 variable stack access prohibited for !root", + .result_unpriv = REJECT, + .result = ACCEPT, +}, +{ + "variable-offset stack write clobbers spilled regs", + .insns = { + /* Dummy instruction; needed because we need to patch the next one + * and we can't patch the first instruction. + */ + BPF_MOV64_IMM(BPF_REG_6, 0), + /* Make R0 a map ptr */ + BPF_LD_MAP_FD(BPF_REG_0, 0), + /* Get an unknown value */ + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0), + /* Make it small and 8-byte aligned */ + BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 8), + BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16), + /* Add it to fp. We now have either fp-8 or fp-16, but + * we don't know which. + */ + BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10), + /* Spill R0(map ptr) into stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8), + /* Dereference the unknown value for a stack write */ + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + /* Fill the register back into R2 */ + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8), + /* Try to dereference R2 for a memory load */ + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8), + BPF_EXIT_INSN(), + }, + .fixup_map_hash_8b = { 1 }, + /* The unpriviledged case is not too interesting; variable + * stack access is rejected. + */ + .errstr_unpriv = "R2 variable stack access prohibited for !root", + .result_unpriv = REJECT, + /* In the priviledged case, dereferencing a spilled-and-then-filled + * register is rejected because the previous variable offset stack + * write might have overwritten the spilled pointer (i.e. we lose track + * of the spilled register when we analyze the write). + */ + .errstr = "R2 invalid mem access 'inv'", + .result = REJECT, +}, +{ "indirect variable-offset stack access, unbounded", .insns = { BPF_MOV64_IMM(BPF_REG_2, 6), @@ -63,7 +158,7 @@ BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "R4 unbounded indirect variable offset stack access", + .errstr = "invalid unbounded variable-offset indirect access to stack R4", .result = REJECT, .prog_type = BPF_PROG_TYPE_SOCK_OPS, }, @@ -88,7 +183,7 @@ BPF_EXIT_INSN(), }, .fixup_map_hash_8b = { 5 }, - .errstr = "R2 max value is outside of stack bound", + .errstr = "invalid variable-offset indirect access to stack R2", .result = REJECT, .prog_type = BPF_PROG_TYPE_LWT_IN, }, @@ -113,7 +208,7 @@ BPF_EXIT_INSN(), }, .fixup_map_hash_8b = { 5 }, - .errstr = "R2 min value is outside of stack bound", + .errstr = "invalid variable-offset indirect access to stack R2", .result = REJECT, .prog_type = BPF_PROG_TYPE_LWT_IN, }, @@ -138,7 +233,7 @@ BPF_EXIT_INSN(), }, .fixup_map_hash_8b = { 5 }, - .errstr = "invalid indirect read from stack var_off", + .errstr = "invalid indirect read from stack R2 var_off", .result = REJECT, .prog_type = BPF_PROG_TYPE_LWT_IN, }, @@ -163,7 +258,7 @@ BPF_EXIT_INSN(), }, .fixup_map_hash_8b = { 5 }, - .errstr = "invalid indirect read from stack var_off", + .errstr = "invalid indirect read from stack R2 var_off", .result = REJECT, .prog_type = BPF_PROG_TYPE_LWT_IN, }, @@ -189,7 +284,7 @@ BPF_EXIT_INSN(), }, .fixup_map_hash_8b = { 6 }, - .errstr_unpriv = "R2 stack pointer arithmetic goes out of range, prohibited for !root", + .errstr_unpriv = "R2 variable stack access prohibited for !root", .result_unpriv = REJECT, .result = ACCEPT, .prog_type = BPF_PROG_TYPE_CGROUP_SKB, @@ -217,7 +312,7 @@ BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "invalid indirect read from stack var_off", + .errstr = "invalid indirect read from stack R4 var_off", .result = REJECT, .prog_type = BPF_PROG_TYPE_SOCK_OPS, }, |