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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2024-07-29 15:51:30 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-08-29 18:36:13 +0300
commitcd19f1799c32ba7b874474b1b968815ce5364f73 (patch)
treed111793549e52bb49e349a54e2109420dad64d49
parentc1e55020534c4aafbc38d8f5c4583ff30755ac18 (diff)
downloadlinux-cd19f1799c32ba7b874474b1b968815ce5364f73.tar.xz
Input: MT - limit max slots
commit 99d3bf5f7377d42f8be60a6b9cb60fb0be34dceb upstream. syzbot is reporting too large allocation at input_mt_init_slots(), for num_slots is supplied from userspace using ioctl(UI_DEV_CREATE). Since nobody knows possible max slots, this patch chose 1024. Reported-by: syzbot <syzbot+0122fa359a69694395d5@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=0122fa359a69694395d5 Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: George Kennedy <george.kennedy@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/input/input-mt.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index 14b53dac1253..6b04a674f832 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -46,6 +46,9 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
return 0;
if (mt)
return mt->num_slots != num_slots ? -EINVAL : 0;
+ /* Arbitrary limit for avoiding too large memory allocation. */
+ if (num_slots > 1024)
+ return -EINVAL;
mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL);
if (!mt)