================================================================== BUG: KASAN: use-after-free in walk_stackframe+0x11c/0x260 arch/riscv/kernel/stacktrace.c:57 Read of size 8 at addr ffffaf8008393d50 by task syz-executor.1/3380 CPU: 0 PID: 3380 Comm: syz-executor.1 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 [] walk_stackframe+0x11c/0x260 arch/riscv/kernel/stacktrace.c:57 [] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:146 [] stack_trace_save+0xa6/0xd8 kernel/stacktrace.c:122 [] save_stack+0x112/0x16c mm/page_owner.c:121 [] __set_page_owner+0x48/0x136 mm/page_owner.c:183 The buggy address belongs to the page: page:ffffaf807a899158 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x88593 flags: 0x8800000000(section=17|node=0|zone=0) raw: 0000008800000000 ffffaf807aa68c78 ffffaf807aac4b68 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 0, migratetype Unmovable, gfp_mask 0x500dc0(GFP_USER|__GFP_ZERO|__GFP_ACCOUNT), pid 3367, ts 1480468295500, free_ts 1483570467300 __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 pmd_alloc_one include/asm-generic/pgalloc.h:126 [inline] __pmd_alloc+0x4e/0x4cc mm/memory.c:4877 pmd_alloc include/linux/mm.h:2243 [inline] __handle_mm_fault+0xa44/0x23a4 mm/memory.c:4667 handle_mm_fault+0x296/0x674 mm/memory.c:4803 do_page_fault+0x308/0xa3c arch/riscv/mm/fault.c:323 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_pages.part.0+0xe0/0xf6 mm/page_alloc.c:5485 free_pages+0xe/0x18 mm/page_alloc.c:5482 pmd_free include/asm-generic/pgalloc.h:142 [inline] free_pmd_range mm/memory.c:266 [inline] free_pud_range mm/memory.c:284 [inline] free_p4d_range mm/memory.c:318 [inline] free_pgd_range+0x8b0/0xc54 mm/memory.c:398 free_pgtables+0x1bc/0x1c8 mm/memory.c:430 exit_mmap+0x168/0x412 mm/mmap.c:3179 __mmput kernel/fork.c:1114 [inline] mmput+0xee/0x2c2 kernel/fork.c:1135 exit_mm kernel/exit.c:507 [inline] do_exit+0x6f2/0x18fc kernel/exit.c:793 do_group_exit+0x90/0x17e kernel/exit.c:935 get_signal+0x3b8/0x1754 kernel/signal.c:2862 do_signal arch/riscv/kernel/signal.c:271 [inline] do_notify_resume+0x11a/0xa56 arch/riscv/kernel/signal.c:317 ret_from_exception+0x0/0x10 Memory state around the buggy address: ffffaf8008393c00: 00 00 00 00 00 00 00 00 ff ff ff ff 00 00 00 00 ffffaf8008393c80: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff >ffffaf8008393d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffffaf8008393d80: ff ff ff ff f1 f1 f1 f1 00 00 00 f3 f3 f3 f3 f3 ffffaf8008393e00: 00 00 00 00 00 00 00 00 00 00 00 00 ff ff ff ff ==================================================================