Vegard Nossum 1147c9cdd0 drm: fix leak of uninitialized data to userspace ... ...so drm_getunique() is trying to copy some uninitialized data to userspace. The ECX register contains the number of words that are left to copy -- so there are 5 * 4 = 20 bytes left. The offset of the first uninitialized byte (counting from the start of the string) is also 20 (i.e. 0xf65d2294&((1 << 5)-1) == 20). So somebody tried to copy 40 bytes when the string was only 19 long. In drm_set_busid() we have this code: dev->unique_len = 40; dev->unique = drm_alloc(dev->unique_len + 1, DRM_MEM_DRIVER); ... len = snprintf(dev->unique, dev->unique_len, pci:%04x:%02x:%02x.%d", ...so it seems that dev->unique is never updated to reflect the actual length of the string. The remaining bytes (20 in this case) are random uninitialized bytes that are copied into userspace. This patch fixes the problem by setting dev->unique_len after the snprintf(). airlied- I've had to fix this up to store the alloced size so we have it for drm_free later. Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Vegard Nossum <vegardno@thuin.ifi.uio.no> Signed-off-by: Dave Airlie <airlied@redhat.com>		2008-12-29 17:47:22 +10:00
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drm	drm: fix leak of uninitialized data to userspace	2008-12-29 17:47:22 +10:00
Makefile	drm: reorganise drm tree to be more future proof.	2008-07-14 10:45:01 +10:00