================================================================== BUG: KASAN: use-after-free in tcindex_set_parms+0x17fd/0x1a00 net/sched/cls_tcindex.c:455 Write of size 16 at addr ffff8880a1cfe630 by task syz-executor556/9549 CPU: 1 PID: 9549 Comm: syz-executor556 Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:641 tcindex_set_parms+0x17fd/0x1a00 net/sched/cls_tcindex.c:455 tcindex_change+0x203/0x2e0 net/sched/cls_tcindex.c:518 tc_new_tfilter+0xa59/0x20b0 net/sched/cls_api.c:2103 rtnetlink_rcv_msg+0x810/0xad0 net/core/rtnetlink.c:5431 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2478 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6b9/0x7d0 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0xec/0x1b0 net/socket.c:2430 do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441739 Code: e8 5c ad 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffd9cd96ed8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441739 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 00000000006cc018 R08: 0000000120080522 R09: 0000000120080522 R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000402600 R13: 0000000000402690 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 1: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] call_usermodehelper_setup+0x98/0x300 kernel/umh.c:386 kobject_uevent_env+0xcfb/0x11f0 lib/kobject_uevent.c:613 tty_register_device_attr+0x475/0x6f0 drivers/tty/tty_io.c:3166 tty_register_device drivers/tty/tty_io.c:3079 [inline] tty_register_driver+0x42d/0x800 drivers/tty/tty_io.c:3350 ttyprintk_init+0x282/0x2cd drivers/char/ttyprintk.c:199 do_one_initcall+0x10a/0x7d0 init/main.c:1152 do_initcall_level init/main.c:1225 [inline] do_initcalls init/main.c:1241 [inline] do_basic_setup init/main.c:1261 [inline] kernel_init_freeable+0x501/0x5ae init/main.c:1445 kernel_init+0xd/0x1bb init/main.c:1352 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 2511: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:476 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 call_usermodehelper_freeinfo kernel/umh.c:48 [inline] umh_complete kernel/umh.c:62 [inline] umh_complete+0x81/0x90 kernel/umh.c:51 call_usermodehelper_exec_async+0x459/0x710 kernel/umh.c:122 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8880a1cfe600 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 48 bytes inside of 192-byte region [ffff8880a1cfe600, ffff8880a1cfe6c0) The buggy address belongs to the page: page:ffffea0002873f80 refcount:1 mapcount:0 mapping:ffff8880aa000000 index:0xffff8880a1cfef00 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002882508 ffff8880aa001138 ffff8880aa000000 raw: ffff8880a1cfef00 ffff8880a1cfe000 000000010000000a 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a1cfe500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a1cfe580: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a1cfe600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a1cfe680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880a1cfe700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================