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authorDan Rosenberg <drosenberg@vsecurity.com>2010-09-22 13:05:09 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-09-26 17:18:27 -0700
commita3bec3ef92a0395e64b5ac67640f420bfabe1bab (patch)
treef79ed15d6437af0dcff57f5d37043c927b153e74
parente675865c92e66331dba733c544eb53b3d6c45eaa (diff)
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drivers/video/sis/sis_main.c: prevent reading uninitialized stack memory
commit fd02db9de73faebc51240619c7c7f99bee9f65c7 upstream. The FBIOGET_VBLANK device ioctl allows unprivileged users to read 16 bytes of uninitialized stack memory, because the "reserved" member of the fb_vblank struct declared on the stack is not altered or zeroed before being copied back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> Cc: Thomas Winischhofer <thomas@winischhofer.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/video/sis/sis_main.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/video/sis/sis_main.c b/drivers/video/sis/sis_main.c
index 559bf1727a2..b52f8e4ef1f 100644
--- a/drivers/video/sis/sis_main.c
+++ b/drivers/video/sis/sis_main.c
@@ -1701,6 +1701,9 @@ static int sisfb_ioctl(struct fb_info *info, unsigned int cmd,
break;
case FBIOGET_VBLANK:
+
+ memset(&sisvbblank, 0, sizeof(struct fb_vblank));
+
sisvbblank.count = 0;
sisvbblank.flags = sisfb_setupvbblankflags(ivideo, &sisvbblank.vcount, &sisvbblank.hcount);