syzbot has found a reproducer for the following issue on: HEAD commit: 15ef2f78c49d Merge tag 'input-for-v7.2-rc7' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11cfe279580000 kernel config: https://syzkaller.appspot.com/x/.config?x=1d67342c314f228d dashboard link: https://syzkaller.appspot.com/bug?extid=b72767277f29b6407083 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15cfe279580000
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: [email protected] ================================================================== BUG: KASAN: use-after-free in ptep_get include/linux/pgtable.h:495 [inline] BUG: KASAN: use-after-free in filemap_map_folio_range mm/filemap.c:3820 [inline] BUG: KASAN: use-after-free in filemap_map_pages+0x1b75/0x1f80 mm/filemap.c:3955 Read of size 8 at addr ffff88803f851a00 by task syz-executor403/6035 CPU: 2 UID: 0 PID: 6035 Comm: syz-executor403 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 ptep_get include/linux/pgtable.h:495 [inline] filemap_map_folio_range mm/filemap.c:3820 [inline] filemap_map_pages+0x1b75/0x1f80 mm/filemap.c:3955 do_fault_around mm/memory.c:5818 [inline] do_read_fault mm/memory.c:5851 [inline] do_fault+0x985/0x1750 mm/memory.c:5994 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6379 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6517 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686 do_user_addr_fault+0x74c/0x12f0 arch/x86/mm/fault.c:1394 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0010:fault_in_readable+0xde/0x190 mm/gup.c:2161 Code: 68 46 ae ff 4c 89 f0 48 85 c0 0f 85 bf 00 00 00 e8 77 4c ae ff 0f 01 cb 0f ae e8 4c 89 fb 4d 85 ff 75 31 eb 48 e8 62 4c ae ff <44> 8a 33 e8 5a 4c ae ff 48 81 c3 00 10 00 00 31 ff 48 81 e3 00 f0 RSP: 0018:ffffc90003a87af8 EFLAGS: 00050293 RAX: 0000000000000000 RBX: 00007fe62c200000 RCX: ffffffff825c2758 RDX: ffff888033b84a80 RSI: ffffffff825c271e RDI: ffff888033b84a80 RBP: 00007fe62c200001 R08: 0000000000000006 R09: 00007fe62c200001 R10: 00007fe62c200000 R11: 0000000000000000 R12: 0000000000000001 R13: 1ffff92000750f60 R14: 0000000000000000 R15: 00007fe62c200000 fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:106 generic_perform_write+0x863/0xa40 mm/filemap.c:4413 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3424 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1050 fs/read_write.c:687 ksys_pwrite64 fs/read_write.c:794 [inline] __do_sys_pwrite64 fs/read_write.c:802 [inline] __se_sys_pwrite64 fs/read_write.c:799 [inline] __x64_sys_pwrite64+0x1eb/0x250 fs/read_write.c:799 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe62c7fce5e Code: 08 0f 85 f5 e2 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 90 41 57 41 56 4d 89 c6 41 55 4d 89 cd 41 54 55 53 48 83 ec 08 RSP: 002b:00007fe62b9fe1a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007fe62b9fe6c0 RCX: 00007fe62c7fce5e RDX: 0000000000000001 RSI: 00007fe62c200000 RDI: 0000000000000003 RBP: 0000000000000021 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffd0 R13: 0000000000000000 R14: 00007ffdde346d90 R15: 00007ffdde346e78 </TASK> The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888000000000 pfn:0x3f851 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: ffff888000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Unmovable, gfp_mask 0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_COMP), pid 6004, tgid 6004 (cmp), ts 79653237963, free_ts 79740307238 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490 alloc_pages_noprof+0x1a/0x160 mm/mempolicy.c:2581 pagetable_alloc_noprof include/linux/mm.h:3685 [inline] pmd_alloc_one_noprof include/asm-generic/pgalloc.h:143 [inline] __pmd_alloc+0x3b/0x950 mm/memory.c:6772 pmd_alloc include/linux/mm.h:3601 [inline] __handle_mm_fault+0xa9c/0x2a00 mm/memory.c:6469 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 page last free pid 6002 tgid 6002 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 __pagetable_free include/linux/mm.h:3695 [inline] pagetable_free include/linux/mm.h:3719 [inline] pagetable_dtor_free include/linux/mm.h:3818 [inline] __tlb_remove_table include/asm-generic/tlb.h:221 [inline] __tlb_remove_table_free mm/mmu_gather.c:228 [inline] tlb_remove_table_rcu+0x2cf/0x380 mm/mmu_gather.c:291 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2897 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 Memory state around the buggy address: ffff88803f851900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803f851980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88803f851a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88803f851a80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803f851b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== ---------------- Code disassembly (best guess): 0: 68 46 ae ff 4c push $0x4cffae46 5: 89 f0 mov %esi,%eax 7: 48 85 c0 test %rax,%rax a: 0f 85 bf 00 00 00 jne 0xcf 10: e8 77 4c ae ff call 0xffae4c8c 15: 0f 01 cb stac 18: 0f ae e8 lfence 1b: 4c 89 fb mov %r15,%rbx 1e: 4d 85 ff test %r15,%r15 21: 75 31 jne 0x54 23: eb 48 jmp 0x6d 25: e8 62 4c ae ff call 0xffae4c8c * 2a: 44 8a 33 mov (%rbx),%r14b <-- trapping instruction 2d: e8 5a 4c ae ff call 0xffae4c8c 32: 48 81 c3 00 10 00 00 add $0x1000,%rbx 39: 31 ff xor %edi,%edi 3b: 48 rex.W 3c: 81 .byte 0x81 3d: e3 00 jrcxz 0x3f 3f: f0 lock --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.
