diff options
Diffstat (limited to 'kernel/seccomp.c')
| -rw-r--r-- | kernel/seccomp.c | 114 |
1 files changed, 61 insertions, 53 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index b35c21503a36..301bbc24739c 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -39,7 +39,7 @@ * is only needed for handling filters shared across tasks. * @prev: points to a previously installed, or inherited, filter * @len: the number of instructions in the program - * @insns: the BPF program instructions to evaluate + * @insnsi: the BPF program instructions to evaluate * * seccomp_filter objects are organized in a tree linked via the @prev * pointer. For any task, it appears to be a singly-linked list starting @@ -54,8 +54,7 @@ struct seccomp_filter { atomic_t usage; struct seccomp_filter *prev; - unsigned short len; /* Instruction count */ - struct sock_filter_int insnsi[]; + struct sk_filter *prog; }; /* Limit any path through the tree to 256KB worth of instructions. */ @@ -104,60 +103,59 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen) u32 k = ftest->k; switch (code) { - case BPF_S_LD_W_ABS: + case BPF_LD | BPF_W | BPF_ABS: ftest->code = BPF_LDX | BPF_W | BPF_ABS; /* 32-bit aligned and not out of bounds. */ if (k >= sizeof(struct seccomp_data) || k & 3) return -EINVAL; continue; - case BPF_S_LD_W_LEN: + case BPF_LD | BPF_W | BPF_LEN: ftest->code = BPF_LD | BPF_IMM; ftest->k = sizeof(struct seccomp_data); continue; - case BPF_S_LDX_W_LEN: + case BPF_LDX | BPF_W | BPF_LEN: ftest->code = BPF_LDX | BPF_IMM; ftest->k = sizeof(struct seccomp_data); continue; /* Explicitly include allowed calls. */ - case BPF_S_RET_K: - case BPF_S_RET_A: - case BPF_S_ALU_ADD_K: - case BPF_S_ALU_ADD_X: - case BPF_S_ALU_SUB_K: - case BPF_S_ALU_SUB_X: - case BPF_S_ALU_MUL_K: - case BPF_S_ALU_MUL_X: - case BPF_S_ALU_DIV_X: - case BPF_S_ALU_AND_K: - case BPF_S_ALU_AND_X: - case BPF_S_ALU_OR_K: - case BPF_S_ALU_OR_X: - case BPF_S_ALU_XOR_K: - case BPF_S_ALU_XOR_X: - case BPF_S_ALU_LSH_K: - case BPF_S_ALU_LSH_X: - case BPF_S_ALU_RSH_K: - case BPF_S_ALU_RSH_X: - case BPF_S_ALU_NEG: - case BPF_S_LD_IMM: - case BPF_S_LDX_IMM: - case BPF_S_MISC_TAX: - case BPF_S_MISC_TXA: - case BPF_S_ALU_DIV_K: - case BPF_S_LD_MEM: - case BPF_S_LDX_MEM: - case BPF_S_ST: - case BPF_S_STX: - case BPF_S_JMP_JA: - case BPF_S_JMP_JEQ_K: - case BPF_S_JMP_JEQ_X: - case BPF_S_JMP_JGE_K: - case BPF_S_JMP_JGE_X: - case BPF_S_JMP_JGT_K: - case BPF_S_JMP_JGT_X: - case BPF_S_JMP_JSET_K: - case BPF_S_JMP_JSET_X: - sk_decode_filter(ftest, ftest); + case BPF_RET | BPF_K: + case BPF_RET | BPF_A: + case BPF_ALU | BPF_ADD | BPF_K: + case BPF_ALU | BPF_ADD | BPF_X: + case BPF_ALU | BPF_SUB | BPF_K: + case BPF_ALU | BPF_SUB | BPF_X: + case BPF_ALU | BPF_MUL | BPF_K: + case BPF_ALU | BPF_MUL | BPF_X: + case BPF_ALU | BPF_DIV | BPF_K: + case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU | BPF_AND | BPF_K: + case BPF_ALU | BPF_AND | BPF_X: + case BPF_ALU | BPF_OR | BPF_K: + case BPF_ALU | BPF_OR | BPF_X: + case BPF_ALU | BPF_XOR | BPF_K: + case BPF_ALU | BPF_XOR | BPF_X: + case BPF_ALU | BPF_LSH | BPF_K: + case BPF_ALU | BPF_LSH | BPF_X: + case BPF_ALU | BPF_RSH | BPF_K: + case BPF_ALU | BPF_RSH | BPF_X: + case BPF_ALU | BPF_NEG: + case BPF_LD | BPF_IMM: + case BPF_LDX | BPF_IMM: + case BPF_MISC | BPF_TAX: + case BPF_MISC | BPF_TXA: + case BPF_LD | BPF_MEM: + case BPF_LDX | BPF_MEM: + case BPF_ST: + case BPF_STX: + case BPF_JMP | BPF_JA: + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP | BPF_JSET | BPF_X: continue; default: return -EINVAL; @@ -189,7 +187,8 @@ static u32 seccomp_run_filters(int syscall) * value always takes priority (ignoring the DATA). */ for (f = current->seccomp.filter; f; f = f->prev) { - u32 cur_ret = sk_run_filter_int_seccomp(&sd, f->insnsi); + u32 cur_ret = SK_RUN_FILTER(f->prog, (void *)&sd); + if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION)) ret = cur_ret; } @@ -215,12 +214,12 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) return -EINVAL; for (filter = current->seccomp.filter; filter; filter = filter->prev) - total_insns += filter->len + 4; /* include a 4 instr penalty */ + total_insns += filter->prog->len + 4; /* include a 4 instr penalty */ if (total_insns > MAX_INSNS_PER_PATH) return -ENOMEM; /* - * Installing a seccomp filter requires that the task have + * Installing a seccomp filter requires that the task has * CAP_SYS_ADMIN in its namespace or be running with no_new_privs. * This avoids scenarios where unprivileged tasks can affect the * behavior of privileged children. @@ -256,19 +255,25 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) /* Allocate a new seccomp_filter */ ret = -ENOMEM; - filter = kzalloc(sizeof(struct seccomp_filter) + - sizeof(struct sock_filter_int) * new_len, + filter = kzalloc(sizeof(struct seccomp_filter), GFP_KERNEL|__GFP_NOWARN); if (!filter) goto free_prog; - ret = sk_convert_filter(fp, fprog->len, filter->insnsi, &new_len); - if (ret) + filter->prog = kzalloc(sk_filter_size(new_len), + GFP_KERNEL|__GFP_NOWARN); + if (!filter->prog) goto free_filter; + + ret = sk_convert_filter(fp, fprog->len, filter->prog->insnsi, &new_len); + if (ret) + goto free_filter_prog; kfree(fp); atomic_set(&filter->usage, 1); - filter->len = new_len; + filter->prog->len = new_len; + + sk_filter_select_runtime(filter->prog); /* * If there is an existing filter, make it the prev and don't drop its @@ -278,6 +283,8 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) current->seccomp.filter = filter; return 0; +free_filter_prog: + kfree(filter->prog); free_filter: kfree(filter); free_prog: @@ -330,6 +337,7 @@ void put_seccomp_filter(struct task_struct *tsk) while (orig && atomic_dec_and_test(&orig->usage)) { struct seccomp_filter *freeme = orig; orig = orig->prev; + sk_filter_free(freeme->prog); kfree(freeme); } } |