Hello:
This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@xxxxxxxxxx>:
On Mon, 13 Jun 2022 16:34:49 -0700 you wrote:
> With latest llvm15, test_varlen failed with the following verifier log:
>
> 17: (85) call bpf_probe_read_kernel_str#115 ; R0_w=scalar(smin=-4095,smax=256)
> 18: (bf) r1 = r0 ; R0_w=scalar(id=1,smin=-4095,smax=256) R1_w=scalar(id=1,smin=-4095,smax=256)
> 19: (67) r1 <<= 32 ; R1_w=scalar(smax=1099511627776,umax=18446744069414584320,var_off=(0x0; 0xffffffff00000000),s32_min=0,s32_max=0,u32_max=)
> 20: (bf) r2 = r1 ; R1_w=scalar(id=2,smax=1099511627776,umax=18446744069414584320,var_off=(0x0; 0xffffffff00000000),s32_min=0,s32_max=0,u32)
> 21: (c7) r2 s>>= 32 ; R2=scalar(smin=-2147483648,smax=256)
> ; if (len >= 0) {
> 22: (c5) if r2 s< 0x0 goto pc+7 ; R2=scalar(umax=256,var_off=(0x0; 0x1ff))
> ; payload4_len1 = len;
> 23: (18) r2 = 0xffffc90000167418 ; R2_w=map_value(off=1048,ks=4,vs=1572,imm=0)
> 25: (63) *(u32 *)(r2 +0) = r0 ; R0=scalar(id=1,smin=-4095,smax=256) R2_w=map_value(off=1048,ks=4,vs=1572,imm=0)
> 26: (77) r1 >>= 32 ; R1_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
> ; payload += len;
> 27: (18) r6 = 0xffffc90000167424 ; R6_w=map_value(off=1060,ks=4,vs=1572,imm=0)
> 29: (0f) r6 += r1 ; R1_w=Pscalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R6_w=map_value(off=1060,ks=4,vs=1572,umax=4294967295,var_off=(0)
> ; len = bpf_probe_read_kernel_str(payload, MAX_LEN, &buf_in2[0]);
> 30: (bf) r1 = r6 ; R1_w=map_value(off=1060,ks=4,vs=1572,umax=4294967295,var_off=(0x0; 0xffffffff)) R6_w=map_value(off=1060,ks=4,vs=1572,um)
> 31: (b7) r2 = 256 ; R2_w=256
> 32: (18) r3 = 0xffffc90000164100 ; R3_w=map_value(off=256,ks=4,vs=1056,imm=0)
> 34: (85) call bpf_probe_read_kernel_str#115
> R1 unbounded memory access, make sure to bounds check any such access
> processed 27 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
> -- END PROG LOAD LOG --
> libbpf: failed to load program 'handler32_signed'
>
> [...]
Here is the summary with links:
- [bpf-next] selftests/bpf: Fix test_varlen verification failure with latest llvm
https://git.kernel.org/bpf/bpf-next/c/96752e1ec0e0
You are awesome, thank you!
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