================================================================== BUG: KASAN: use-after-free in memcmp+0x172/0x1c0 lib/string.c:681 Read of size 8 at addr ffff8880437a9002 by task syz-executor.3/7833 CPU: 0 PID: 7833 Comm: syz-executor.3 Not tainted 6.5.0-rc5-syzkaller-00243-g9106536c1aa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 memcmp+0x172/0x1c0 lib/string.c:681 memcmp include/linux/fortify-string.h:728 [inline] ntfs_init_from_boot fs/ntfs3/super.c:860 [inline] ntfs_fill_super+0x6e0/0x43b0 fs/ntfs3/super.c:1141 get_tree_bdev+0x43e/0x7d0 fs/super.c:1318 vfs_get_tree+0x88/0x350 fs/super.c:1519 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f07f1c7e1ea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f07f2a03ee8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f07f2a03f80 RCX: 00007f07f1c7e1ea RDX: 0000000020000500 RSI: 0000000020000200 RDI: 00007f07f2a03f40 RBP: 0000000020000500 R08: 00007f07f2a03f80 R09: 000000000000004d R10: 000000000000004d R11: 0000000000000202 R12: 0000000020000200 R13: 00007f07f2a03f40 R14: 000000000001f446 R15: 0000000020000040 The buggy address belongs to the physical page: page:ffffea00010dea40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x437a9 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000000 ffffea00010dea88 ffffea00010deb88 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 7829, tgid 7829 (syz-executor.5), ts 334495440657, free_ts 334562317193 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570 prep_new_page mm/page_alloc.c:1577 [inline] get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477 __folio_alloc+0x16/0x40 mm/page_alloc.c:4509 vma_alloc_folio+0x156/0x890 mm/mempolicy.c:2253 wp_page_copy mm/memory.c:3081 [inline] do_wp_page+0x159a/0x3710 mm/memory.c:3446 handle_pte_fault mm/memory.c:4955 [inline] __handle_mm_fault+0x1af7/0x3b80 mm/memory.c:5079 handle_mm_fault+0x2ab/0x9d0 mm/memory.c:5233 do_user_addr_fault+0x2e7/0xfc0 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1486 [inline] exc_page_fault+0x5c/0xd0 arch/x86/mm/fault.c:1542 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1161 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348 free_unref_page_list+0xe6/0xb30 mm/page_alloc.c:2489 release_pages+0x32a/0x14e0 mm/swap.c:1042 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:97 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline] tlb_flush_mmu mm/mmu_gather.c:299 [inline] tlb_finish_mmu+0x14b/0x7e0 mm/mmu_gather.c:391 exit_mmap+0x2db/0x960 mm/mmap.c:3215 __mmput+0x12a/0x4d0 kernel/fork.c:1348 mmput+0x62/0x70 kernel/fork.c:1370 exit_mm kernel/exit.c:567 [inline] do_exit+0x9b4/0x2a20 kernel/exit.c:861 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024 get_signal+0x23ea/0x2770 kernel/signal.c:2881 arch_do_signal_or_restart+0x89/0x5f0 arch/x86/kernel/signal.c:308 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880437a8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880437a8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880437a9000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880437a9080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880437a9100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== ================================================================== BUG: KASAN: use-after-free in memcmp+0x1a3/0x1c0 lib/string.c:692 Read of size 1 at addr ffff8880437a9002 by task syz-executor.3/7833 CPU: 1 PID: 7833 Comm: syz-executor.3 Tainted: G B 6.5.0-rc5-syzkaller-00243-g9106536c1aa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 memcmp+0x1a3/0x1c0 lib/string.c:692 memcmp include/linux/fortify-string.h:728 [inline] ntfs_init_from_boot fs/ntfs3/super.c:860 [inline] ntfs_fill_super+0x6e0/0x43b0 fs/ntfs3/super.c:1141 get_tree_bdev+0x43e/0x7d0 fs/super.c:1318 vfs_get_tree+0x88/0x350 fs/super.c:1519 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f07f1c7e1ea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f07f2a03ee8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f07f2a03f80 RCX: 00007f07f1c7e1ea RDX: 0000000020000500 RSI: 0000000020000200 RDI: 00007f07f2a03f40 RBP: 0000000020000500 R08: 00007f07f2a03f80 R09: 000000000000004d R10: 000000000000004d R11: 0000000000000202 R12: 0000000020000200 R13: 00007f07f2a03f40 R14: 000000000001f446 R15: 0000000020000040 The buggy address belongs to the physical page: page:ffffea00010dea40 refcount:1 mapcount:0 mapping:ffff888039987ab8 index:0x6e pfn:0x437a9 memcg:ffff8880805a2000 aops:shmem_aops ino:37 dentry name:"memfd:syzkaller" flags: 0xfff4000008001e(referenced|uptodate|dirty|lru|swapbacked|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff4000008001e ffffea00010deb88 ffffea00010dea88 ffff888039987ab8 raw: 000000000000006e 0000000000000000 00000001ffffffff ffff8880805a2000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 7845, tgid 7844 (syz-executor.5), ts 335126346445, free_ts 334562317193 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570 prep_new_page mm/page_alloc.c:1577 [inline] get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477 __folio_alloc+0x16/0x40 mm/page_alloc.c:4509 vma_alloc_folio+0x156/0x890 mm/mempolicy.c:2253 shmem_alloc_folio+0xb5/0x170 mm/shmem.c:1579 shmem_alloc_and_acct_folio+0x168/0x5e0 mm/shmem.c:1603 shmem_get_folio_gfp+0xce7/0x1b60 mm/shmem.c:1948 shmem_get_folio mm/shmem.c:2079 [inline] shmem_write_begin+0x15c/0x390 mm/shmem.c:2573 generic_perform_write+0x278/0x600 mm/filemap.c:3923 __generic_file_write_iter+0x1f9/0x240 mm/filemap.c:4018 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4044 call_write_iter include/linux/fs.h:1877 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x650/0xe40 fs/read_write.c:584 ksys_write+0x12f/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1161 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348 free_unref_page_list+0xe6/0xb30 mm/page_alloc.c:2489 release_pages+0x32a/0x14e0 mm/swap.c:1042 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:97 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline] tlb_flush_mmu mm/mmu_gather.c:299 [inline] tlb_finish_mmu+0x14b/0x7e0 mm/mmu_gather.c:391 exit_mmap+0x2db/0x960 mm/mmap.c:3215 __mmput+0x12a/0x4d0 kernel/fork.c:1348 mmput+0x62/0x70 kernel/fork.c:1370 exit_mm kernel/exit.c:567 [inline] do_exit+0x9b4/0x2a20 kernel/exit.c:861 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024 get_signal+0x23ea/0x2770 kernel/signal.c:2881 arch_do_signal_or_restart+0x89/0x5f0 arch/x86/kernel/signal.c:308 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880437a8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880437a8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880437a9000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff8880437a9080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880437a9100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ntfs3: loop3: Alternative boot signature is not NTFS.