================================================================== BUG: KASAN: stack-out-of-bounds in user_mode arch/x86/include/asm/ptrace.h:136 [inline] BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x17fc/0x1ef0 arch/x86/kernel/unwind_orc.c:455 Read of size 8 at addr ffffc900080c7b88 by task syz-executor.1/14148 CPU: 0 PID: 14148 Comm: syz-executor.1 Not tainted 6.2.0-next-20230221-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319 print_report mm/kasan/report.c:430 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:536 user_mode arch/x86/include/asm/ptrace.h:136 [inline] unwind_next_frame+0x17fc/0x1ef0 arch/x86/kernel/unwind_orc.c:455 arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x90/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:491 irq_work_queue_on+0xd6/0x1a0 kernel/irq_work.c:140 irq_work_single+0x1e4/0x260 kernel/irq_work.c:211 __flush_smp_call_function_queue+0x4a3/0xad0 kernel/smp.c:668 __sysvec_call_function_single+0xce/0x4f0 arch/x86/kernel/smp.c:248 sysvec_call_function_single+0x92/0xc0 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:__unix_dgram_recvmsg+0x481/0xb90 net/unix/af_unix.c:2530 Code: 08 00 00 00 00 c7 40 14 00 00 00 00 48 8b 84 24 20 01 00 00 65 48 2b 04 25 28 00 00 00 0f 85 19 06 00 00 48 81 c4 28 01 00 00 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 ec b3 b6 f8 49 8d bc RSP: 0018:ffffc900080c79a0 EFLAGS: 00000296 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000d76a000 RDX: 0000000000040000 RSI: ffffffff88cdefbe RDI: ffffc900080c77c0 RBP: ffff88802a0f83c0 R08: 0000000000000001 R09: ffffc900080c77c7 R10: fffff52001018ef8 R11: 0000000000000000 R12: ffff888022ae0800 R13: 0000000000000000 R14: 0000000000000000 R15: ffffc900080c7940 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0000:___sys_recvmsg+0x0/0x180 net/socket.c:2755 Code: 00 00 75 1d 48 81 c4 a0 00 00 00 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 bc f2 ff ff ff eb b0 e8 d4 14 0a 02 0f 1f 40 00 <48> b8 00 00 00 00 00 fc ff df 41 57 45 89 c7 41 56 49 89 f6 41 55 RSP: 0000:1ffff1100f3b14ed EFLAGS: 00000000 ORIG_RAX: ffffffff8bfc5030 RAX: 0000000020366340 RBX: a00f17450db64400 RCX: 000000000000d98a RDX: ffffffff880c7ba2 RSI: ffff888074d79800 RDI: 0000000041b58ab3 RBP: 0000000000000000 R08: ffffc900080c7db0 R09: 0000000000000002 R10: 0000000000000000 R11: 1ffff92001018f6e R12: ffffffff8a16912d R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 The buggy address belongs to stack of task syz-executor.1/14148 and is located at offset 24 in frame: ___sys_recvmsg+0x0/0x180 net/socket.c:2446 This frame has 3 objects: [32, 40) 'iov' [64, 72) 'uaddr' [96, 224) 'iovstack' The buggy address belongs to the virtual mapping at [ffffc900080c0000, ffffc900080c9000) created by: kernel_clone+0xeb/0xa10 kernel/fork.c:2684 The buggy address belongs to the physical page: page:ffffea0001d85040 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76141 memcg:ffff88807cfc8782 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88807cfc8782 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 14138, tgid 14138 (syz-executor.1), ts 1298364489033, free_ts 1214843223567 prep_new_page mm/page_alloc.c:2552 [inline] get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4339 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5605 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2283 vm_area_alloc_pages mm/vmalloc.c:2942 [inline] __vmalloc_area_node mm/vmalloc.c:3010 [inline] __vmalloc_node_range+0xb8a/0x1300 mm/vmalloc.c:3180 alloc_thread_stack_node kernel/fork.c:311 [inline] dup_task_struct kernel/fork.c:984 [inline] copy_process+0x1320/0x76c0 kernel/fork.c:2100 kernel_clone+0xeb/0xa10 kernel/fork.c:2684 __do_sys_clone+0xba/0x100 kernel/fork.c:2825 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 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:1453 [inline] free_pcp_prepare+0x4de/0x930 mm/page_alloc.c:1503 free_unref_page_prepare mm/page_alloc.c:3401 [inline] free_unref_page_list+0x176/0xcd0 mm/page_alloc.c:3542 release_pages+0xcd7/0x1380 mm/swap.c:1042 tlb_batch_pages_flush+0xa8/0x1a0 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+0x205/0x7d0 mm/mmap.c:3047 __mmput+0x128/0x4c0 kernel/fork.c:1209 mmput+0x60/0x70 kernel/fork.c:1231 exit_mm kernel/exit.c:563 [inline] do_exit+0x9d7/0x2b60 kernel/exit.c:856 do_group_exit+0xd4/0x2a0 kernel/exit.c:1019 get_signal+0x2315/0x25b0 kernel/signal.c:2859 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffffc900080c7a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f3 f3 ffffc900080c7b00: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >ffffc900080c7b80: f1 f1 00 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 00 ^ ffffc900080c7c00: 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 00 00 ffffc900080c7c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: 08 00 or %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 c7 add %al,%bh 6: 40 14 00 adc $0x0,%al 9: 00 00 add %al,(%rax) b: 00 48 8b add %cl,-0x75(%rax) e: 84 24 20 test %ah,(%rax,%riz,1) 11: 01 00 add %eax,(%rax) 13: 00 65 48 add %ah,0x48(%rbp) 16: 2b 04 25 28 00 00 00 sub 0x28,%eax 1d: 0f 85 19 06 00 00 jne 0x63c 23: 48 81 c4 28 01 00 00 add $0x128,%rsp * 2a: 44 89 e8 mov %r13d,%eax <-- trapping instruction 2d: 5b pop %rbx 2e: 5d pop %rbp 2f: 41 5c pop %r12 31: 41 5d pop %r13 33: 41 5e pop %r14 35: 41 5f pop %r15 37: c3 retq 38: e8 ec b3 b6 f8 callq 0xf8b6b429 3d: 49 rex.WB 3e: 8d .byte 0x8d 3f: bc .byte 0xbc