Re: [PATCH v8 4/8] bpftool: Ensure task comm is always NUL-terminated
From: Justin Stitt <justinstitt@google.com>
Date: 2024-09-12 21:14:52
Also in:
bpf, dri-devel, linux-fsdevel, linux-mm, linux-security-module, linux-trace-kernel, selinux
Hi, On Wed, Aug 28, 2024 at 11:03:17AM GMT, Yafang Shao wrote:
quoted hunk ↗ jump to hunk
Let's explicitly ensure the destination string is NUL-terminated. This way, it won't be affected by changes to the source string. Signed-off-by: Yafang Shao <redacted> Reviewed-by: Quentin Monnet <qmo@kernel.org> --- tools/bpf/bpftool/pids.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c index 9b898571b49e..23f488cf1740 100644 --- a/tools/bpf/bpftool/pids.c +++ b/tools/bpf/bpftool/pids.c@@ -54,6 +54,7 @@ static void add_ref(struct hashmap *map, struct pid_iter_entry *e) ref = &refs->refs[refs->ref_cnt]; ref->pid = e->pid; memcpy(ref->comm, e->comm, sizeof(ref->comm)); + ref->comm[sizeof(ref->comm) - 1] = '\0';
...
quoted hunk ↗ jump to hunk
refs->ref_cnt++; return;@@ -77,6 +78,7 @@ static void add_ref(struct hashmap *map, struct pid_iter_entry *e) ref = &refs->refs[0]; ref->pid = e->pid; memcpy(ref->comm, e->comm, sizeof(ref->comm)); + ref->comm[sizeof(ref->comm) - 1] = '\0';
Excuse my ignorance, do we not have a strscpy() equivalent usable in bpf code?
refs->ref_cnt = 1; refs->has_bpf_cookie = e->has_bpf_cookie; refs->bpf_cookie = e->bpf_cookie; -- 2.43.5
Thanks Justin