From: Phillip Potter phil@philpotter.co.uk
commit 19ab233989d0f7ab1de19a036e247afa4a0a1e9c upstream.
Use kzalloc() rather than kmalloc() for the dynamically allocated parts of the colormap in fb_alloc_cmap_gfp, to prevent a leak of random kernel data to userspace under certain circumstances.
Fixes a KMSAN-found infoleak bug reported by syzbot at: https://syzkaller.appspot.com/bug?id=741578659feabd108ad9e06696f0c1f2e69c4b6...
Reported-by: syzbot+47fa9c9c648b765305b9@syzkaller.appspotmail.com Cc: stable stable@vger.kernel.org Reviewed-by: Geert Uytterhoeven geert+renesas@glider.be Signed-off-by: Phillip Potter phil@philpotter.co.uk Link: https://lore.kernel.org/r/20210331220719.1499743-1-phil@philpotter.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/video/fbdev/core/fbcmap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/video/fbdev/core/fbcmap.c +++ b/drivers/video/fbdev/core/fbcmap.c @@ -101,17 +101,17 @@ int fb_alloc_cmap_gfp(struct fb_cmap *cm if (!len) return 0;
- cmap->red = kmalloc(size, flags); + cmap->red = kzalloc(size, flags); if (!cmap->red) goto fail; - cmap->green = kmalloc(size, flags); + cmap->green = kzalloc(size, flags); if (!cmap->green) goto fail; - cmap->blue = kmalloc(size, flags); + cmap->blue = kzalloc(size, flags); if (!cmap->blue) goto fail; if (transp) { - cmap->transp = kmalloc(size, flags); + cmap->transp = kzalloc(size, flags); if (!cmap->transp) goto fail; } else {