4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ben Hutchings <ben.hutchi...@codethink.co.uk>
Extracted from commit 31fd85816dbe "bpf: permits narrower load from
bpf program context fields".
Cc: Daniel Borkmann <dan...@iogearbox.net>
Cc: Alexei Starovoitov <a...@kernel.org>
Signed-off-by: Ben Hutchings <ben.hutchi...@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
kernel/bpf/verifier.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -694,7 +694,7 @@ static bool is_ctx_reg(struct verifier_e
* if t==write && value_regno==-1, some unknown value is stored into memory
* if t==read && value_regno==-1, don't care what we read from memory
*/
-static int check_mem_access(struct verifier_env *env, u32 regno, int off,
+static int check_mem_access(struct verifier_env *env, int insn_idx, u32 regno,
int off,
int bpf_size, enum bpf_access_type t,
int value_regno)
{
@@ -758,7 +758,7 @@ static int check_mem_access(struct verif
return err;
}
-static int check_xadd(struct verifier_env *env, struct bpf_insn *insn)
+static int check_xadd(struct verifier_env *env, int insn_idx, struct bpf_insn
*insn)
{
struct reg_state *regs = env->cur_state.regs;
int err;
@@ -791,13 +791,13 @@ static int check_xadd(struct verifier_en
}
/* check whether atomic_add can read the memory */
- err = check_mem_access(env, insn->dst_reg, insn->off,
+ err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
BPF_SIZE(insn->code), BPF_READ, -1);
if (err)
return err;
/* check whether atomic_add can write into the same memory */
- return check_mem_access(env, insn->dst_reg, insn->off,
+ return check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
BPF_SIZE(insn->code), BPF_WRITE, -1);
}
@@ -1836,7 +1836,7 @@ static int do_check(struct verifier_env
/* check that memory (src_reg + off) is readable,
* the state of dst_reg will be updated by this func
*/
- err = check_mem_access(env, insn->src_reg, insn->off,
+ err = check_mem_access(env, insn_idx, insn->src_reg,
insn->off,
BPF_SIZE(insn->code), BPF_READ,
insn->dst_reg);
if (err)
@@ -1875,7 +1875,7 @@ static int do_check(struct verifier_env
enum bpf_reg_type *prev_dst_type, dst_reg_type;
if (BPF_MODE(insn->code) == BPF_XADD) {
- err = check_xadd(env, insn);
+ err = check_xadd(env, insn_idx, insn);
if (err)
return err;
insn_idx++;
@@ -1894,7 +1894,7 @@ static int do_check(struct verifier_env
dst_reg_type = regs[insn->dst_reg].type;
/* check that memory (dst_reg + off) is writeable */
- err = check_mem_access(env, insn->dst_reg, insn->off,
+ err = check_mem_access(env, insn_idx, insn->dst_reg,
insn->off,
BPF_SIZE(insn->code), BPF_WRITE,
insn->src_reg);
if (err)
@@ -1929,7 +1929,7 @@ static int do_check(struct verifier_env
}
/* check that memory (dst_reg + off) is writeable */
- err = check_mem_access(env, insn->dst_reg, insn->off,
+ err = check_mem_access(env, insn_idx, insn->dst_reg,
insn->off,
BPF_SIZE(insn->code), BPF_WRITE,
-1);
if (err)
