================================================================== BUG: KASAN: slab-use-after-free in taprio_dump_tc_entries net/sched/sch_taprio.c:2287 [inline] BUG: KASAN: slab-use-after-free in taprio_dump+0x857/0xd50 net/sched/sch_taprio.c:2400 Read of size 4 at addr ffff88801fb12cc4 by task syz-executor.2/15872 CPU: 1 PID: 15872 Comm: syz-executor.2 Not tainted 6.8.0-rc4-next-20240214-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 taprio_dump_tc_entries net/sched/sch_taprio.c:2287 [inline] taprio_dump+0x857/0xd50 net/sched/sch_taprio.c:2400 tc_fill_qdisc+0x6a9/0x1210 net/sched/sch_api.c:952 qdisc_notify+0x2ec/0x4b0 net/sched/sch_api.c:1053 tc_modify_qdisc+0x1c58/0x1e40 net/sched/sch_api.c:1748 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6609 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3c/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f96bfc7dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f96befff0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f96bfdabf80 RCX: 00007f96bfc7dda9 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004 RBP: 00007f96bfcca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f96bfdabf80 R15: 00007fff43a9dfc8 Allocated by task 15872: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x1d9/0x360 mm/slub.c:4013 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:711 [inline] taprio_change+0x1030/0x42d0 net/sched/sch_taprio.c:1861 qdisc_change net/sched/sch_api.c:1416 [inline] tc_modify_qdisc+0x190d/0x1e40 net/sched/sch_api.c:1746 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6609 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3c/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Freed by task 15: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:586 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2122 [inline] slab_free mm/slub.c:4296 [inline] kfree+0x14a/0x380 mm/slub.c:4406 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 __do_softirq+0x2bc/0x943 kernel/softirq.c:554 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:2734 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:2838 switch_schedules net/sched/sch_taprio.c:212 [inline] advance_sched+0x940/0xca0 net/sched/sch_taprio.c:973 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x595/0xd00 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x107/0x3a0 arch/x86/kernel/apic/apic.c:1082 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1076 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 The buggy address belongs to the object at ffff88801fb12c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 196 bytes inside of freed 512-byte region [ffff88801fb12c00, ffff88801fb12e00) The buggy address belongs to the physical page: page:ffffea00007ec400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1fb10 head:ffffea00007ec400 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000840 ffff888014c41c80 ffffea00029b9800 dead000000000002 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 9072830940, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 __alloc_pages+0x256/0x6a0 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2191 allocate_slab mm/slub.c:2354 [inline] new_slab+0x84/0x2f0 mm/slub.c:2407 ___slab_alloc+0xc73/0x1260 mm/slub.c:3541 __slab_alloc mm/slub.c:3626 [inline] __slab_alloc_node mm/slub.c:3679 [inline] slab_alloc_node mm/slub.c:3851 [inline] kmalloc_node_trace+0x262/0x3a0 mm/slub.c:4021 kmalloc_node include/linux/slab.h:606 [inline] kzalloc_node include/linux/slab.h:722 [inline] blkg_alloc+0xd6/0x7f0 block/blk-cgroup.c:312 blkcg_init_disk+0xb3/0x1f0 block/blk-cgroup.c:1422 __alloc_disk_node+0x2d2/0x590 block/genhd.c:1364 __blk_alloc_disk+0xb3/0x140 block/genhd.c:1404 brd_alloc+0x2d4/0x670 drivers/block/brd.c:338 brd_init+0x104/0x1d0 drivers/block/brd.c:425 do_one_initcall+0x238/0x830 init/main.c:1233 do_initcall_level+0x157/0x210 init/main.c:1295 do_initcalls+0x3f/0x80 init/main.c:1311 page_owner free stack trace missing Memory state around the buggy address: ffff88801fb12b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801fb12c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801fb12c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801fb12d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801fb12d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================