On Tue, Oct 19, 2021 at 01:44:24PM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: d999ade1cc86 Merge tag 'perf-tools-fixes-for-v5.15-2021-10.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17d85d34b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=b5d8cfd89abd92bf > dashboard link: https://syzkaller.appspot.com/bug?extid=9df2568864dedf79db36 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9df2568864dedf79db36@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================================ > UBSAN: array-index-out-of-bounds in drivers/usb/host/ehci-hub.c:754:39 > index 254 is out of range for type 'u32 [15]' > CPU: 0 PID: 11514 Comm: syz-executor.1 Not tainted 5.15.0-rc5-syzkaller #0 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 This should already be fixed by https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/drivers/usb/host/ehci-hub.c?h=usb-next&id=846cbf98cbef20376b1a95fa3734c435543f3519 (although it can't be tested if there is no reproducer). That commit is scheduled to go into 5.16-rc1. This isn't really a bug, because the pointer doesn't get used in cases where the index is beyond the end of the array. Alan Stern
