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authorJakub Kicinski <kuba@kernel.org>2024-05-02 21:05:13 +0200
committerJakub Kicinski <kuba@kernel.org>2024-05-02 21:06:25 +0200
commite958da0ddbe831197a0023251880a4a09d5ba268 (patch)
treeeacded26f9563064a44fd1afe730493898adadb9 /kernel/bpf/verifier.c
parentMerge branch 'bnxt_en-updates-for-net-next' (diff)
parentMerge tag 'net-6.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netd... (diff)
downloadlinux-e958da0ddbe831197a0023251880a4a09d5ba268.tar.xz
linux-e958da0ddbe831197a0023251880a4a09d5ba268.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. Conflicts: include/linux/filter.h kernel/bpf/core.c 66e13b615a0c ("bpf: verifier: prevent userspace memory access") d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT") https://lore.kernel.org/all/20240429114939.210328b0@canb.auug.org.au/ No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c33
1 files changed, 31 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 87ff414899cf..719c633e500a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -18469,8 +18469,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
f = fdget(fd);
map = __bpf_map_get(f);
if (IS_ERR(map)) {
- verbose(env, "fd %d is not pointing to valid bpf_map\n",
- insn[0].imm);
+ verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
return PTR_ERR(map);
}
@@ -19886,6 +19885,36 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
goto next_insn;
}
+ /* Make it impossible to de-reference a userspace address */
+ if (BPF_CLASS(insn->code) == BPF_LDX &&
+ (BPF_MODE(insn->code) == BPF_PROBE_MEM ||
+ BPF_MODE(insn->code) == BPF_PROBE_MEMSX)) {
+ struct bpf_insn *patch = &insn_buf[0];
+ u64 uaddress_limit = bpf_arch_uaddress_limit();
+
+ if (!uaddress_limit)
+ goto next_insn;
+
+ *patch++ = BPF_MOV64_REG(BPF_REG_AX, insn->src_reg);
+ if (insn->off)
+ *patch++ = BPF_ALU64_IMM(BPF_ADD, BPF_REG_AX, insn->off);
+ *patch++ = BPF_ALU64_IMM(BPF_RSH, BPF_REG_AX, 32);
+ *patch++ = BPF_JMP_IMM(BPF_JLE, BPF_REG_AX, uaddress_limit >> 32, 2);
+ *patch++ = *insn;
+ *patch++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
+ *patch++ = BPF_MOV64_IMM(insn->dst_reg, 0);
+
+ cnt = patch - insn_buf;
+ new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
+ if (!new_prog)
+ return -ENOMEM;
+
+ delta += cnt - 1;
+ env->prog = prog = new_prog;
+ insn = new_prog->insnsi + i + delta;
+ goto next_insn;
+ }
+
/* Implement LD_ABS and LD_IND with a rewrite, if supported by the program type. */
if (BPF_CLASS(insn->code) == BPF_LD &&
(BPF_MODE(insn->code) == BPF_ABS ||