On Sun, May 29, 2016 at 01:52:44PM -0400, Sasha Levin wrote: > Hi all, > > I've hit the following while fuzzing with syzkaller inside a KVM tools guest > running the latest -next kernel: > > [ 2662.777566] BUG: KASAN: global-out-of-bounds in > do_compute_shiftstate+0x161/0x370 at addr ffffffffb2e686a0 > > [ 2662.777592] Read of size 2 by task syz-executor/30576 > > [ 2662.777676] Address belongs to variable plain_map+0x200/0x3540 > > [ 2662.777727] CPU: 2 PID: 30576 Comm: syz-executor Tainted: G B > 4.6.0-next-20160527-sasha-00024-g6ab0dc9-dirty #3098 > > [ 2662.777792] 1ffff1001635bde7 00000000dc4d92d7 ffff8800b1adefc0 > ffffffffa3fd0b37 > > [ 2662.777826] ffffffff00000002 fffffbfff5deeda4 0000000041b58ab3 > ffffffffae8dd830 > > [ 2662.777862] ffffffffa3fd09c8 ffffffffa23fa2e8 ffff8800b1adef98 > ffff8801d42a20f8 > > [ 2662.777868] Call Trace: > > [ 2662.777935] dump_stack (lib/dump_stack.c:53) > [ 2662.778136] kasan_report_error (include/linux/kasan.h:28 > mm/kasan/report.c:211 mm/kasan/report.c:277) > [ 2662.778265] __asan_report_load2_noabort (mm/kasan/report.c:317) > [ 2662.778318] do_compute_shiftstate (drivers/tty/vt/keyboard.c:386) > [ 2662.778332] fn_null (drivers/tty/vt/keyboard.c:625) > [ 2662.778345] k_spec (drivers/tty/vt/keyboard.c:645) > [ 2662.778361] kbd_event (drivers/tty/vt/keyboard.c:1459 > drivers/tty/vt/keyboard.c:1475) > [ 2662.778907] input_to_handler (drivers/input/input.c:120 (discriminator 3)) > [ 2662.778926] input_pass_values (drivers/input/input.c:148) > [ 2662.778944] input_handle_event (drivers/input/input.c:406) > [ 2662.779015] input_inject_event (include/linux/rcupdate.h:910 > drivers/input/input.c:467) > [ 2662.779034] evdev_do_ioctl (drivers/input/evdev.c:1102) > [ 2662.779271] evdev_ioctl_handler (drivers/input/evdev.c:1302) > [ 2662.779305] evdev_ioctl (drivers/input/evdev.c:1312) > [ 2662.779320] do_vfs_ioctl (fs/ioctl.c:44 fs/ioctl.c:674) > [ 2662.779463] SyS_ioctl (fs/ioctl.c:689 fs/ioctl.c:680) > [ 2662.779511] do_syscall_64 (arch/x86/entry/common.c:350) > [ 2662.779530] entry_SYSCALL64_slow_path (arch/x86/entry/entry_64.S:251) > [ 2662.779535] Memory state around the buggy address: > > [ 2662.779566] ffffffffb2e68580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 > > [ 2662.779579] ffffffffb2e68600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 > > [ 2662.779589] >ffffffffb2e68680: 00 00 00 00 fa fa fa fa 00 00 00 00 00 00 > 00 00 > > [ 2662.779594] ^ > > [ 2662.779604] ffffffffb2e68700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 > > [ 2662.779615] ffffffffb2e68780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00
Any chance you can get the result of what the fuzzer was trying to send over the ioctl so we could try to track this down? thanks, greg k-h
