================================================================== BUG: KASAN: use-after-free in walk_stackframe+0x11c/0x260 arch/riscv/kernel/stacktrace.c:57 Read of size 8 at addr ffffaf80247f3fd0 by task syz-executor.0/4437 CPU: 0 PID: 4437 Comm: syz-executor.0 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 The buggy address belongs to the page: page:ffffaf807b08cc58 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0xa49f3 flags: 0xa000000000(section=20|node=0|zone=0) raw: 000000a000000000 ffffaf807a9a1760 ffffaf807aa7b608 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffff7f 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 2040, ts 3400719901800, free_ts 3403816880300 __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 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline] pte_alloc_one include/asm-generic/pgalloc.h:85 [inline] __pte_alloc+0x96/0x394 mm/memory.c:465 copy_pte_range mm/memory.c:1025 [inline] copy_pmd_range mm/memory.c:1160 [inline] copy_pud_range mm/memory.c:1197 [inline] copy_p4d_range mm/memory.c:1221 [inline] copy_page_range+0x1532/0x236c mm/memory.c:1294 dup_mmap kernel/fork.c:612 [inline] dup_mm+0xb5c/0xe10 kernel/fork.c:1451 copy_mm kernel/fork.c:1503 [inline] copy_process+0x25da/0x3c34 kernel/fork.c:2164 kernel_clone+0xee/0x920 kernel/fork.c:2555 __do_sys_clone+0xf2/0x12e kernel/fork.c:2672 sys_clone+0x32/0x44 kernel/fork.c:2640 ret_from_syscall+0x0/0x2 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_list+0x148/0x7fe mm/page_alloc.c:3441 release_pages+0x3f0/0xad0 mm/swap.c:980 free_pages_and_swap_cache+0x74/0x86 mm/swap_state.c:320 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline] tlb_flush_mmu_free mm/mmu_gather.c:243 [inline] tlb_flush_mmu mm/mmu_gather.c:250 [inline] tlb_finish_mmu+0xe8/0x29a mm/mmu_gather.c:341 exit_mmap+0x170/0x412 mm/mmap.c:3180 __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 __do_sys_exit_group kernel/exit.c:946 [inline] __wake_up_parent+0x0/0x4a kernel/exit.c:944 ret_from_syscall+0x0/0x2 Memory state around the buggy address: ffffaf80247f3e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffffaf80247f3f00: ff ff ff ff ff ff ff ff ff ff ff ff 00 00 00 00 >ffffaf80247f3f80: 00 00 00 00 00 00 00 00 ff ff ff ff 00 00 00 00 ^ ffffaf80247f4000: f1 f1 f1 f1 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 ffffaf80247f4080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================