From: Christophe Leroy Date: Mon, 17 Nov 2025 16:43:43 +0000 (+0100) Subject: scm: Convert put_cmsg() to scoped user access X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1c204914bc4401623a1b242305c583060a0b7e4f;p=thirdparty%2Flinux.git scm: Convert put_cmsg() to scoped user access Replace the open coded implementation with the scoped user access guard. That also corrects the imbalance between masked_user_access_begin() and user_write_access_end(), which would affect PowerPC when it gains masked user access support. No functional change intended. [ tglx: Amend change log ] Signed-off-by: Christophe Leroy Signed-off-by: Thomas Gleixner Link: https://patch.msgid.link/793219313f641eda09a892d06768d2837246bf9f.1763396724.git.christophe.leroy@csgroup.eu --- diff --git a/net/core/scm.c b/net/core/scm.c index 66eaee783e8be..cd87f66671aa0 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -273,17 +273,13 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data) check_object_size(data, cmlen - sizeof(*cm), true); - if (can_do_masked_user_access()) - cm = masked_user_access_begin(cm); - else if (!user_write_access_begin(cm, cmlen)) - goto efault; - - unsafe_put_user(cmlen, &cm->cmsg_len, efault_end); - unsafe_put_user(level, &cm->cmsg_level, efault_end); - unsafe_put_user(type, &cm->cmsg_type, efault_end); - unsafe_copy_to_user(CMSG_USER_DATA(cm), data, - cmlen - sizeof(*cm), efault_end); - user_write_access_end(); + scoped_user_write_access_size(cm, cmlen, efault) { + unsafe_put_user(cmlen, &cm->cmsg_len, efault); + unsafe_put_user(level, &cm->cmsg_level, efault); + unsafe_put_user(type, &cm->cmsg_type, efault); + unsafe_copy_to_user(CMSG_USER_DATA(cm), data, + cmlen - sizeof(*cm), efault); + } } else { struct cmsghdr *cm = msg->msg_control; @@ -301,8 +297,6 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data) msg->msg_controllen -= cmlen; return 0; -efault_end: - user_write_access_end(); efault: return -EFAULT; }