================================================================== BUG: KASAN: stack-out-of-bounds in user_mode arch/x86/include/asm/ptrace.h:131 [inline] BUG: KASAN: stack-out-of-bounds in update_stack_state+0x376/0x5b0 arch/x86/kernel/unwind_frame.c:244 Read of size 8 at addr ffff88802170fe50 by task syz-executor.4/3394 CPU: 0 PID: 3394 Comm: syz-executor.4 Not tainted 5.4.17-syzkaller-01371-gb3fbbf580c21 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b0/0x228 lib/dump_stack.c:118 print_address_description+0x96/0x5d0 mm/kasan/report.c:374 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506 kasan_report+0x26/0x50 mm/kasan/common.c:634 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 user_mode arch/x86/include/asm/ptrace.h:131 [inline] update_stack_state+0x376/0x5b0 arch/x86/kernel/unwind_frame.c:244 unwind_next_frame+0x415/0x870 arch/x86/kernel/unwind_frame.c:311 arch_stack_walk+0xb4/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save_tsk+0x2d5/0x470 kernel/stacktrace.c:151 proc_pid_stack+0x137/0x200 fs/proc/base.c:455 proc_single_show+0xd5/0x130 fs/proc/base.c:757 seq_read+0x4a8/0xdd0 fs/seq_file.c:229 do_loop_readv_writev fs/read_write.c:717 [inline] do_iter_read+0x4a2/0x5b0 fs/read_write.c:938 vfs_readv fs/read_write.c:1000 [inline] do_preadv+0x1f4/0x330 fs/read_write.c:1092 __do_sys_preadv fs/read_write.c:1142 [inline] __se_sys_preadv fs/read_write.c:1137 [inline] __x64_sys_preadv+0x9e/0xb0 fs/read_write.c:1137 do_syscall_64+0xc0/0x100 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45b399 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fbf88980c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fbf889816d4 RCX: 000000000045b399 RDX: 00000000000003a8 RSI: 00000000200017c0 RDI: 0000000000000008 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000850 R14: 00000000004c9c73 R15: 000000000075bfd4 The buggy address belongs to the page: page:ffffea000085c3c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 raw: 4000000000000000 ffffea000085c3c8 ffffea000085c3c8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88802170fd00: f1 f1 f1 f1 00 f2 f2 f2 00 00 f3 f3 00 00 00 00 ffff88802170fd80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 >ffff88802170fe00: 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 00 00 ^ ffff88802170fe80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802170ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================