RE: [PATCH V2] net: bpf: switch over to memdup_user()
From: John Fastabend <john.fastabend@gmail.com>
Date: 2021-10-18 16:27:01
Also in:
bpf, lkml
Qing Wang wrote:
This patch fixes the following Coccinelle warning: net/bpf/test_run.c:361:8-15: WARNING opportunity for memdup_user net/bpf/test_run.c:1055:8-15: WARNING opportunity for memdup_user Use memdup_user rather than duplicating its implementation This is a little bit restricted to reduce false positives Signed-off-by: Qing Wang <redacted> --- net/bpf/test_run.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-)
LGTM, but subject line should be '[PATCH bpf-next v2]' there is no reason to push to fixes trees here. Also might be worth noting that the original kzalloc could have just been a kalloc because copy_from_user will zero any extra bytes. Acked-by: John Fastabend <john.fastabend@gmail.com>
quoted hunk ↗ jump to hunk
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 5296087..fbda8f5 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c@@ -358,13 +358,9 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog, return -EINVAL; if (ctx_size_in) { - info.ctx = kzalloc(ctx_size_in, GFP_USER); - if (!info.ctx) - return -ENOMEM; - if (copy_from_user(info.ctx, ctx_in, ctx_size_in)) { - err = -EFAULT; - goto out; - } + info.ctx = memdup_user(ctx_in, ctx_size_in); + if (IS_ERR(info.ctx)) + return PTR_ERR(info.ctx); } else { info.ctx = NULL; }@@ -392,7 +388,6 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog, copy_to_user(&uattr->test.retval, &info.retval, sizeof(u32))) err = -EFAULT; -out: kfree(info.ctx); return err; }@@ -1052,13 +1047,9 @@ int bpf_prog_test_run_syscall(struct bpf_prog *prog, return -EINVAL; if (ctx_size_in) { - ctx = kzalloc(ctx_size_in, GFP_USER); - if (!ctx) - return -ENOMEM; - if (copy_from_user(ctx, ctx_in, ctx_size_in)) { - err = -EFAULT; - goto out; - } + ctx = memdup_user(ctx_in, ctx_size_in); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); } rcu_read_lock_trace();-- 2.7.4