From 40b2519d7566266d7eafd3c5232c73a497640bca Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 16 Nov 2023 11:15:10 -0800 Subject: [PATCH] samples: Replace strlcpy() with strscpy() strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated[1]. Additionally, it returns the size of the source string, not the resulting size of the destination string. In an effort to remove strlcpy() completely[2], replace strlcpy() here with strscpy(). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1] Link: https://github.com/KSPP/linux/issues/89 [2] Cc: Masami Hiramatsu Cc: Valentin Schneider Cc: "Steven Rostedt (Google)" Cc: Chuck Lever Cc: Geliang Tang Cc: Greg Kroah-Hartman Cc: Christophe JAILLET Cc: Thomas Gleixner Cc: Arnd Bergmann Acked-by: "Steven Rostedt (Google)" Link: https://lore.kernel.org/r/20231116191510.work.550-kees@kernel.org Signed-off-by: Kees Cook --- samples/trace_events/trace-events-sample.h | 2 +- samples/v4l/v4l2-pci-skeleton.c | 10 +++++----- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h index 1c6b843b8c4e..23f923ccd529 100644 --- a/samples/trace_events/trace-events-sample.h +++ b/samples/trace_events/trace-events-sample.h @@ -305,7 +305,7 @@ TRACE_EVENT(foo_bar, ), TP_fast_assign( - strlcpy(__entry->foo, foo, 10); + strscpy(__entry->foo, foo, 10); __entry->bar = bar; memcpy(__get_dynamic_array(list), lst, __length_of(lst) * sizeof(int)); diff --git a/samples/v4l/v4l2-pci-skeleton.c b/samples/v4l/v4l2-pci-skeleton.c index a61f94db18d9..69ef788d9e3b 100644 --- a/samples/v4l/v4l2-pci-skeleton.c +++ b/samples/v4l/v4l2-pci-skeleton.c @@ -291,8 +291,8 @@ static int skeleton_querycap(struct file *file, void *priv, { struct skeleton *skel = video_drvdata(file); - strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver)); - strlcpy(cap->card, "V4L2 PCI Skeleton", sizeof(cap->card)); + strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver)); + strscpy(cap->card, "V4L2 PCI Skeleton", sizeof(cap->card)); snprintf(cap->bus_info, sizeof(cap->bus_info), "PCI:%s", pci_name(skel->pdev)); return 0; @@ -597,11 +597,11 @@ static int skeleton_enum_input(struct file *file, void *priv, i->type = V4L2_INPUT_TYPE_CAMERA; if (i->index == 0) { i->std = SKEL_TVNORMS; - strlcpy(i->name, "S-Video", sizeof(i->name)); + strscpy(i->name, "S-Video", sizeof(i->name)); i->capabilities = V4L2_IN_CAP_STD; } else { i->std = 0; - strlcpy(i->name, "HDMI", sizeof(i->name)); + strscpy(i->name, "HDMI", sizeof(i->name)); i->capabilities = V4L2_IN_CAP_DV_TIMINGS; } return 0; @@ -845,7 +845,7 @@ static int skeleton_probe(struct pci_dev *pdev, const struct pci_device_id *ent) /* Initialize the video_device structure */ vdev = &skel->vdev; - strlcpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name)); + strscpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name)); /* * There is nothing to clean up, so release is set to an empty release * function. The release callback must be non-NULL. -- 2.34.1