================================================================== BUG: KASAN: use-after-free in walk_stackframe+0x11c/0x260 arch/riscv/kernel/stacktrace.c:57 Read of size 8 at addr ffffaf80218c7fa0 by task syz-executor.1/2055 CPU: 0 PID: 2055 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 The buggy address belongs to the page: page:ffffaf807afb87f8 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa1ac7 flags: 0xa000000000(section=20|node=0|zone=0) raw: 000000a000000000 ffffaf807a85a358 ffffaf807a8e2630 0000000000000000 raw: 0000000000000000 ffffaf800febdde0 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 0x400dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO), pid 2667, ts 926938640500, free_ts 928570857100 __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 clear_user arch/riscv/include/asm/uaccess.h:346 [inline] padzero+0xb8/0xde fs/binfmt_elf.c:141 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 __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: ffffaf80218c7e80: 00 00 00 00 ff ff ff ff 00 00 00 00 00 00 00 00 ffffaf80218c7f00: 00 00 00 00 ff ff ff ff 00 00 00 00 00 00 00 00 >ffffaf80218c7f80: 00 00 00 00 ff ff ff ff 00 00 00 00 00 00 00 00 ^ ffffaf80218c8000: f1 f1 f1 f1 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 ffffaf80218c8080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================