# \[PATCH\] zero-fill colormap in drivers/video/fbdev/core/fbcmap.c - Subsystems: FRAMEBUFFER LAYER, FRAMEBUFFER CORE, THE REST - Maintainers: Helge Deller, Simona Vetter, Linus Torvalds - Status: LANDED (19ab233989d0 ยท 2021-04-10 09:12) - Landed in mainline as 19ab233989d0 on 2021-04-10. - List: linux-fbdev - 4 messages, 3 authors - Page: https://ratatoskr.run/linux-fbdev/2021/03/6323230/t ## \[PATCH\] zero-fill colormap in drivers/video/fbdev/core/fbcmap.c - From: Phillip Potter \ - Date: 2021-03-31 22:08:15 - Message: https://ratatoskr.run/linux-fbdev/2021/03/6323230.md ```text 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=741578659feabd108ad9e06696f0c1f2e69c4b6e Reported-by: Signed-off-by: Phillip Potter --- 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 { -- 2.30.2 ``` ## Re: \[PATCH\] zero-fill colormap in drivers/video/fbdev/core/fbcmap.c - From: Geert Uytterhoeven \ - Date: 2021-04-01 09:57:03 - Message: https://ratatoskr.run/linux-fbdev/2021/04/6323775.md ```text On Thu, Apr 1, 2021 at 12:09 AM Phillip Potter [ref] wrote: > 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=741578659feabd108ad9e06696f0c1f2e69c4b6e > > Reported-by: > Signed-off-by: Phillip Potter Reviewed-by: Geert Uytterhoeven Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ``` ## Re: \[PATCH\] zero-fill colormap in drivers/video/fbdev/core/fbcmap.c - From: Phillip Potter \ - Date: 2021-04-02 08:57:17 - Message: https://ratatoskr.run/linux-fbdev/2021/04/6325033.md ```text On Thu, Apr 01, 2021 at 11:55:50AM +0200, Geert Uytterhoeven wrote: > On Thu, Apr 1, 2021 at 12:09 AM Phillip Potter [ref] wrote: > > 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=741578659feabd108ad9e06696f0c1f2e69c4b6e > > > > Reported-by: > > Signed-off-by: Phillip Potter > > Reviewed-by: Geert Uytterhoeven > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds Dear Geert Thank you for your review :-) Regards, Phil ``` ## Re: \[PATCH\] zero-fill colormap in drivers/video/fbdev/core/fbcmap.c - From: Greg KH \ - Date: 2021-04-02 15:37:29 - Message: https://ratatoskr.run/linux-fbdev/2021/04/6325389.md ```text On Wed, Mar 31, 2021 at 11:07:19PM +0100, Phillip Potter wrote: > 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=741578659feabd108ad9e06696f0c1f2e69c4b6e > > Reported-by: > Signed-off-by: Phillip Potter > --- > drivers/video/fbdev/core/fbcmap.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) Daniel, want me to take this? thanks, greg k-h ```