[PATCH v3 01/16] umh: Capture the pid in umh_pipe_setup
From: Eric W. Biederman <hidden>
Date: 2020-07-02 16:47:32
Also in:
bpf, linux-fsdevel, lkml
Subsystem:
kernel usermode helper, the rest · Maintainers:
Luis Chamberlain, Linus Torvalds
The pid in struct subprocess_info is only used by umh_clean_and_save_pid to write the pid into umh_info. Instead always capture the pid on struct umh_info in umh_pipe_setup, removing code that is specific to user mode drivers from the common user path of user mode helpers. v1: https://lkml.kernel.org/r/87h7uygf9i.fsf_-_@x220.int.ebiederm.org v2: https://lkml.kernel.org/r/875zb97iix.fsf_-_@x220.int.ebiederm.org Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <redacted> --- include/linux/umh.h | 1 - kernel/umh.c | 5 ++--- 2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/include/linux/umh.h b/include/linux/umh.h
index 0c08de356d0d..aae16a0ebd0f 100644
--- a/include/linux/umh.h
+++ b/include/linux/umh.h@@ -25,7 +25,6 @@ struct subprocess_info { struct file *file; int wait; int retval; - pid_t pid; int (*init)(struct subprocess_info *info, struct cred *new); void (*cleanup)(struct subprocess_info *info); void *data;
diff --git a/kernel/umh.c b/kernel/umh.c
index 79f139a7ca03..c2a582b3a2bf 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c@@ -102,7 +102,6 @@ static int call_usermodehelper_exec_async(void *data) commit_creds(new); - sub_info->pid = task_pid_nr(current); if (sub_info->file) { retval = do_execve_file(sub_info->file, sub_info->argv, sub_info->envp);
@@ -468,6 +467,7 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) umh_info->pipe_to_umh = to_umh[1]; umh_info->pipe_from_umh = from_umh[0]; + umh_info->pid = task_pid_nr(current); return 0; }
@@ -476,13 +476,12 @@ static void umh_clean_and_save_pid(struct subprocess_info *info) struct umh_info *umh_info = info->data; /* cleanup if umh_pipe_setup() was successful but exec failed */ - if (info->pid && info->retval) { + if (info->retval) { fput(umh_info->pipe_to_umh); fput(umh_info->pipe_from_umh); } argv_free(info->argv); - umh_info->pid = info->pid; } /**
--
2.25.0