==================================================================
BUG: Double free or freeing an invalid pointer
Unexpected shadow byte: 0xFB
CPU: 1 PID: 6919 Comm: syz-executor0 Not tainted 4.9.40-ged32335 #11
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801ca3afb70 ffffffff81d8d829 ffff8801da001b40 ffff8801d86bd360
 ffff8801d86bd370 ffffffff82a6eb38 0000000000000282 ffff8801ca3afb98
 ffffffff81537a3c 00000000fffffffb ffff8801da001b40 ffff8801d86bd360
Call Trace:
 [<ffffffff81d8d829>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d8d829>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81537a3c>] kasan_object_err+0x1c/0x70 mm/kasan/report.c:160
 [<ffffffff81538273>] kasan_report_double_free+0x53/0x80 mm/kasan/report.c:181
 [<ffffffff8153762d>] kasan_slab_free+0x9d/0xc0 mm/kasan/kasan.c:562
 [<ffffffff815341b0>] slab_free_hook mm/slub.c:1355 [inline]
 [<ffffffff815341b0>] slab_free_freelist_hook mm/slub.c:1377 [inline]
 [<ffffffff815341b0>] slab_free mm/slub.c:2958 [inline]
 [<ffffffff815341b0>] kfree+0xf0/0x2f0 mm/slub.c:3878
 [<ffffffff82a6eb38>] keychord_write+0x628/0x820 drivers/input/misc/keychord.c:319
 [<ffffffff815659a3>] __vfs_write+0x103/0x680 fs/read_write.c:510
 [<ffffffff81569ad0>] vfs_write+0x170/0x4e0 fs/read_write.c:560
 [<ffffffff8156d4c9>] SYSC_write fs/read_write.c:607 [inline]
 [<ffffffff8156d4c9>] SyS_write+0xd9/0x1b0 fs/read_write.c:599
 [<ffffffff838a06c5>] entry_SYSCALL_64_fastpath+0x23/0xc6
Object at ffff8801d86bd360, in cache kmalloc-16 size: 16
Allocated:
PID = 6919
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:495
 set_track mm/kasan/kasan.c:507 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:598
 __kmalloc+0x11d/0x310 mm/slub.c:3741
 kmalloc include/linux/slab.h:495 [inline]
 kzalloc include/linux/slab.h:636 [inline]
 keychord_write+0x6d/0x820 drivers/input/misc/keychord.c:243
 __vfs_write+0x103/0x680 fs/read_write.c:510
 vfs_write+0x170/0x4e0 fs/read_write.c:560
 SYSC_write fs/read_write.c:607 [inline]
 SyS_write+0xd9/0x1b0 fs/read_write.c:599
 entry_SYSCALL_64_fastpath+0x23/0xc6
Freed:
PID = 6920
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:495
 set_track mm/kasan/kasan.c:507 [inline]
 kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:571
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kfree+0xf0/0x2f0 mm/slub.c:3878
 keychord_write+0x15d/0x820 drivers/input/misc/keychord.c:261
 __vfs_write+0x103/0x680 fs/read_write.c:510
 vfs_write+0x170/0x4e0 fs/read_write.c:560
 SYSC_write fs/read_write.c:607 [inline]
 SyS_write+0xd9/0x1b0 fs/read_write.c:599
 entry_SYSCALL_64_fastpath+0x23/0xc6
==================================================================
keychord: unsupported version 40
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7028 comm=syz-executor7
netlink: 6 bytes leftover after parsing attributes in process `syz-executor4'.
netlink: 6 bytes leftover after parsing attributes in process `syz-executor4'.
netlink: 1 bytes leftover after parsing attributes in process `syz-executor4'.
PF_BRIDGE: RTM_NEWNEIGH with unknown ifindex
PF_BRIDGE: RTM_NEWNEIGH with unknown ifindex
keychord: Insufficient bytes present for header 2
keychord: Insufficient bytes present for header 2
binder: 7302:7305 ioctl 541c 20000ffe returned -22
binder: 7302:7305 ioctl 4b64 20002fff returned -22
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=44260 sclass=netlink_route_socket pig=7317 comm=syz-executor4
binder: 7302:7326 ioctl 540f 20004ffc returned -22
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=44260 sclass=netlink_route_socket pig=7330 comm=syz-executor4
binder: 7302:7326 ioctl 541c 20000ffe returned -22
binder: 7302:7326 ioctl 4b64 20002fff returned -22
binder: 7302:7333 ioctl 540f 20004ffc returned -22
device syz0 entered promiscuous mode
device syz0 left promiscuous mode
device syz0 entered promiscuous mode
sg_write: data in/out 1729298428/132 bytes for SCSI command 0xfd-- guessing data in;
   program syz-executor5 not setting count and/or reply_len properly
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=8378 comm=syz-executor2
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=8387 comm=syz-executor2
binder: 8930:8942 ioctl 5402 20d20000 returned -22
binder: 8930:8957 ioctl 5402 20d20000 returned -22
device sit0 entered promiscuous mode
device sit0 left promiscuous mode
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=511 sclass=netlink_route_socket pig=9966 comm=syz-executor2
binder: 9963:9972 ioctl 4b4d 200cb000 returned -22
binder: 9963:9972 ioctl 4b4d 200cb000 returned -22
binder: 10048:10073 ioctl c018aa3f 2080afe8 returned -22
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=257 sclass=netlink_route_socket pig=10093 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=257 sclass=netlink_route_socket pig=10098 comm=syz-executor0
binder: 10048:10124 ioctl 40082404 205dc000 returned -22
binder: 10048:10125 ioctl c018aa3f 2080afe8 returned -22
binder: 10048:10129 ioctl 40082404 205dc000 returned -22
binder: 10139:10144 ioctl 401054d6 20000000 returned -22
binder: 10139:10161 ioctl 401054d6 20000000 returned -22