This is a note to let you know that I've just added the patch titled

fbdev: zero-fill colormap in fbcmap.c

to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-testing branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will be merged to the char-misc-next branch sometime soon, after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.

From 19ab233989d0f7ab1de19a036e247afa4a0a1e9c Mon Sep 17 00:00:00 2001

From: Phillip Potter phil@philpotter.co.uk Date: Wed, 31 Mar 2021 23:07:19 +0100 Subject: fbdev: zero-fill colormap in fbcmap.c

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 --- drivers/video/fbdev/core/fbcmap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/video/fbdev/core/fbcmap.c b/drivers/video/fbdev/core/fbcmap.c index 757d5c3f620b..ff09e57f3c38 100644 --- 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 *cmap, int len, int transp, gfp_t flags) 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 {