summaryrefslogtreecommitdiff
path: root/kernel/seccomp.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/seccomp.c')
-rw-r--r--kernel/seccomp.c70
1 files changed, 14 insertions, 56 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 4f4402894..245df6b32 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -346,16 +346,13 @@ static inline void seccomp_sync_threads(void)
*/
static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog)
{
- struct seccomp_filter *filter;
- unsigned long fp_size;
- struct sock_filter *fp;
- int new_len;
- long ret;
+ struct seccomp_filter *sfilter;
+ int ret;
if (fprog->len == 0 || fprog->len > BPF_MAXINSNS)
return ERR_PTR(-EINVAL);
+
BUG_ON(INT_MAX / fprog->len < sizeof(struct sock_filter));
- fp_size = fprog->len * sizeof(struct sock_filter);
/*
* Installing a seccomp filter requires that the task has
@@ -368,60 +365,21 @@ static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog)
CAP_SYS_ADMIN) != 0)
return ERR_PTR(-EACCES);
- fp = kzalloc(fp_size, GFP_KERNEL|__GFP_NOWARN);
- if (!fp)
- return ERR_PTR(-ENOMEM);
-
- /* Copy the instructions from fprog. */
- ret = -EFAULT;
- if (copy_from_user(fp, fprog->filter, fp_size))
- goto free_prog;
-
- /* Check and rewrite the fprog via the skb checker */
- ret = bpf_check_classic(fp, fprog->len);
- if (ret)
- goto free_prog;
-
- /* Check and rewrite the fprog for seccomp use */
- ret = seccomp_check_filter(fp, fprog->len);
- if (ret)
- goto free_prog;
-
- /* Convert 'sock_filter' insns to 'bpf_insn' insns */
- ret = bpf_convert_filter(fp, fprog->len, NULL, &new_len);
- if (ret)
- goto free_prog;
-
/* Allocate a new seccomp_filter */
- ret = -ENOMEM;
- filter = kzalloc(sizeof(struct seccomp_filter),
- GFP_KERNEL|__GFP_NOWARN);
- if (!filter)
- goto free_prog;
-
- filter->prog = bpf_prog_alloc(bpf_prog_size(new_len), __GFP_NOWARN);
- if (!filter->prog)
- goto free_filter;
-
- ret = bpf_convert_filter(fp, fprog->len, filter->prog->insnsi, &new_len);
- if (ret)
- goto free_filter_prog;
-
- kfree(fp);
- atomic_set(&filter->usage, 1);
- filter->prog->len = new_len;
+ sfilter = kzalloc(sizeof(*sfilter), GFP_KERNEL | __GFP_NOWARN);
+ if (!sfilter)
+ return ERR_PTR(-ENOMEM);
- bpf_prog_select_runtime(filter->prog);
+ ret = bpf_prog_create_from_user(&sfilter->prog, fprog,
+ seccomp_check_filter);
+ if (ret < 0) {
+ kfree(sfilter);
+ return ERR_PTR(ret);
+ }
- return filter;
+ atomic_set(&sfilter->usage, 1);
-free_filter_prog:
- __bpf_prog_free(filter->prog);
-free_filter:
- kfree(filter);
-free_prog:
- kfree(fp);
- return ERR_PTR(ret);
+ return sfilter;
}
/**