Author: emaste Date: Fri Mar 23 02:33:30 2018 New Revision: 331409 URL: https://svnweb.freebsd.org/changeset/base/331409
Log: MFC r331339: Correct signedness bug in drm_modeset_ctl drm_modeset_ctl() takes a signed in from userland, does a boundscheck, and then uses it to index into a structure and write to it. The boundscheck only checks upper bound, and never checks for nagative values. If the int coming from userland is negative [after conversion] it will bypass the boundscheck, perform a negative index into an array and write to it, causing memory corruption. Note that this is in the "old" drm driver; this issue does not exist in drm2. Reported by: Ilja Van Sprundel <ivansprun...@ioactive.com> Reviewed by: cem Sponsored by: The FreeBSD Foundation Modified: stable/11/sys/dev/drm/drm_irq.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/dev/drm/drm_irq.c ============================================================================== --- stable/11/sys/dev/drm/drm_irq.c Fri Mar 23 02:30:29 2018 (r331408) +++ stable/11/sys/dev/drm/drm_irq.c Fri Mar 23 02:33:30 2018 (r331409) @@ -351,7 +351,7 @@ int drm_modeset_ctl(struct drm_device *dev, void *data goto out; crtc = modeset->crtc; - if (crtc >= dev->num_crtcs) { + if (crtc < 0 || crtc >= dev->num_crtcs) { ret = EINVAL; goto out; } _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"