From 214ff13d9ebbba7940f29bc89669f85f12533083 Mon Sep 17 00:00:00 2001 From: Michel Daenzer Date: Fri, 22 Sep 2006 04:12:11 +1000 Subject: drm: fd.o Bug #7595: Avoid u32 overflows in radeon_check_and_fixup_offset(). The overflows could cause valid offsets to get rejected under some circumstances, e.g. when the framebuffer resides at the very end of the card's address space. Signed-off-by: Dave Airlie --- drivers/char/drm/radeon_state.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'drivers') diff --git a/drivers/char/drm/radeon_state.c b/drivers/char/drm/radeon_state.c index 0433ff80cb7..bcfa1514a4d 100644 --- a/drivers/char/drm/radeon_state.c +++ b/drivers/char/drm/radeon_state.c @@ -42,7 +42,11 @@ static __inline__ int radeon_check_and_fixup_offset(drm_radeon_private_t * drm_file_t * filp_priv, u32 *offset) { - u32 off = *offset; + u64 off = *offset; + u32 fb_start = dev_priv->fb_location; + u32 fb_end = fb_start + dev_priv->fb_size - 1; + u32 gart_start = dev_priv->gart_vm_start; + u32 gart_end = gart_start + dev_priv->gart_size - 1; struct drm_radeon_driver_file_fields *radeon_priv; /* Hrm ... the story of the offset ... So this function converts @@ -62,10 +66,8 @@ static __inline__ int radeon_check_and_fixup_offset(drm_radeon_private_t * /* First, the best case, the offset already lands in either the * framebuffer or the GART mapped space */ - if ((off >= dev_priv->fb_location && - off < (dev_priv->fb_location + dev_priv->fb_size)) || - (off >= dev_priv->gart_vm_start && - off < (dev_priv->gart_vm_start + dev_priv->gart_size))) + if ((off >= fb_start && off <= fb_end) || + (off >= gart_start && off <= gart_end)) return 0; /* Ok, that didn't happen... now check if we have a zero based @@ -78,16 +80,13 @@ static __inline__ int radeon_check_and_fixup_offset(drm_radeon_private_t * } /* Finally, assume we aimed at a GART offset if beyond the fb */ - if (off > (dev_priv->fb_location + dev_priv->fb_size)) - off = off - (dev_priv->fb_location + dev_priv->fb_size) + - dev_priv->gart_vm_start; + if (off > fb_end) + off = off - fb_end - 1 + gart_start; /* Now recheck and fail if out of bounds */ - if ((off >= dev_priv->fb_location && - off < (dev_priv->fb_location + dev_priv->fb_size)) || - (off >= dev_priv->gart_vm_start && - off < (dev_priv->gart_vm_start + dev_priv->gart_size))) { - DRM_DEBUG("offset fixed up to 0x%x\n", off); + if ((off >= fb_start && off <= fb_end) || + (off >= gart_start && off <= gart_end)) { + DRM_DEBUG("offset fixed up to 0x%x\n", (unsigned int)off); *offset = off; return 0; } -- cgit v1.2.3