================================================================== BUG: KASAN: use-after-free in __bfs+0x154/0x394 kernel/locking/lockdep.c:1708 Read of size 8 at addr ffffaf8020bcbf90 by task modprobe/3208 CPU: 0 PID: 3208 Comm: modprobe Not tainted 5.17.0-rc1-syzkaller-00002-g0966d385830d #0 Hardware name: riscv-virtio,qemu (DT) Call Trace: [] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:113 [] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:119 [] __dump_stack lib/dump_stack.c:88 [inline] [] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:106 [] print_address_description.constprop.0+0x2a/0x330 mm/kasan/report.c:255 [] __kasan_report mm/kasan/report.c:442 [inline] [] kasan_report+0x184/0x1e0 mm/kasan/report.c:459 [] check_region_inline mm/kasan/generic.c:183 [inline] [] __asan_load8+0x6e/0x96 mm/kasan/generic.c:256 [] __bfs+0x154/0x394 kernel/locking/lockdep.c:1708 [] __bfs_forwards kernel/locking/lockdep.c:1803 [inline] [] check_path.constprop.0+0x24/0x46 kernel/locking/lockdep.c:2104 [] check_noncircular+0x11a/0x1fe kernel/locking/lockdep.c:2131 The buggy address belongs to the page: page:ffffaf807af7e118 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa0dcb flags: 0xa000000000(section=20|node=0|zone=0) raw: 000000a000000000 ffffaf807ab28348 ffffaf807af7e0d8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 raw: 00000000000007ff page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 2068, ts 844225826700, free_ts 873361264900 __set_page_owner+0x48/0x136 mm/page_owner.c:183 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0xd0/0x10a mm/page_alloc.c:2427 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0x8da/0x12d8 mm/page_alloc.c:4165 __alloc_pages+0x150/0x3b6 mm/page_alloc.c:5389 alloc_pages+0x132/0x2a6 mm/mempolicy.c:2271 alloc_slab_page.constprop.0+0xc2/0xfa mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x76/0x2cc mm/slub.c:2004 ___slab_alloc+0x56e/0x918 mm/slub.c:3018 __slab_alloc.constprop.0+0x50/0x8c mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] __kmalloc_node_track_caller+0x26c/0x362 mm/slub.c:4957 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xee/0x2e4 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:745 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:802 [inline] nsim_dev_trap_report_work+0x1c2/0x5e4 drivers/net/netdevsim/dev.c:843 process_one_work+0x654/0xffe kernel/workqueue.c:2307 worker_thread+0x360/0x8fa kernel/workqueue.c:2454 kthread+0x19e/0x1fa kernel/kthread.c:377 ret_from_exception+0x0/0x10 page last free stack trace: __reset_page_owner+0x4a/0xea mm/page_owner.c:142 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x29c/0x45e mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x6a/0x31e mm/page_alloc.c:3404 free_the_page mm/page_alloc.c:706 [inline] __free_pages+0xe2/0x112 mm/page_alloc.c:5474 __free_slab+0x122/0x27c mm/slub.c:2028 free_slab mm/slub.c:2043 [inline] discard_slab+0x4c/0x7a mm/slub.c:2049 __unfreeze_partials+0x16a/0x18e mm/slub.c:2536 put_cpu_partial+0xf6/0x162 mm/slub.c:2612 __slab_free+0x166/0x29c mm/slub.c:3378 do_slab_free mm/slub.c:3497 [inline] ___cache_free+0x17c/0x354 mm/slub.c:3516 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x7c/0x132 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14c/0x1c8 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x5c/0x98 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] __kmalloc+0x156/0x318 mm/slub.c:4420 kmalloc include/linux/slab.h:586 [inline] tomoyo_realpath_from_path+0x9c/0x3f4 security/tomoyo/realpath.c:254 tomoyo_realpath_nofollow+0xf2/0x10a security/tomoyo/realpath.c:309 Memory state around the buggy address: ffffaf8020bcbe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffffaf8020bcbf00: ff ff ff ff 00 00 00 00 f1 f1 f1 f1 00 f2 f2 f2 >ffffaf8020bcbf80: ff ff ff ff 00 00 00 f3 f3 f3 f3 f3 ff ff ff ff ^ ffffaf8020bcc000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffaf8020bcc080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================