BUG: KASAN: global-out-of-bounds in strscpy+0x807/0x970
From: Jakub Kicinski
Date: Tue Oct 10 2017 - 21:28:18 EST
I'm hitting this on sysctl -a with net-next (4.14-rc4).
I saw that seccomp_actions_logged_handler was introduced
not-so-long-ago by Tyler, is there a fix for this?
[ 753.503760] BUG: KASAN: global-out-of-bounds in strscpy+0x807/0x970
[ 753.510892] Read of size 8 at addr ffffffffa96b97c8 by task sysctl/1787
[ 753.518416]
[ 753.520198] CPU: 1 PID: 1787 Comm: sysctl Not tainted 4.14.0-rc4-debug-00822-g07ec06ef312a #316
[ 753.538598] Call Trace:
[ 753.541449] dump_stack+0xb3/0x140
[ 753.545372] ? _atomic_dec_and_lock+0x2b0/0x2b0
[ 753.550564] ? show_regs_print_info+0x6d/0x6d
[ 753.555562] print_address_description+0x25f/0x440
[ 753.561044] ? strscpy+0x807/0x970
[ 753.564967] kasan_report+0x1b8/0x430
[ 753.569182] ? strscpy+0x807/0x970
[ 753.573107] strscpy+0x807/0x970
[ 753.576838] ? strncpy+0xf0/0xf0
[ 753.580576] ? sched_clock_cpu+0x18/0x290
[ 753.585185] seccomp_actions_logged_handler+0x384/0x8d0
[ 753.591157] ? seccomp_send_sigsys+0xa0/0xa0
[ 753.596046] ? lock_downgrade+0x740/0x740
[ 753.600648] ? get_lock_stats+0x18/0x160
[ 753.605159] ? sysctl_head_grab+0x1b/0xc0
[ 753.609766] ? lock_contended+0x1130/0x1130
[ 753.614566] ? lock_release+0x14e0/0x14e0
[ 753.619171] ? do_raw_spin_trylock+0x1c0/0x1c0
[ 753.624261] ? lock_downgrade+0x660/0x740
[ 753.628858] ? do_raw_spin_lock+0x1f0/0x1f0
[ 753.633657] proc_sys_call_handler+0x216/0x3c0
[ 753.638752] ? proc_sys_permission+0x250/0x250
[ 753.643847] ? do_mmap+0x622/0xf50
[ 753.647772] __vfs_read+0xea/0x9a0
[ 753.651696] ? vfs_copy_file_range+0xc60/0xc60
[ 753.656787] ? security_mmap_file+0x66/0x1d0
[ 753.661686] ? common_file_perm+0x1e0/0x6b0
[ 753.666485] ? vm_mmap_pgoff+0x1b6/0x250
[ 753.670993] ? fsnotify+0x1c80/0x1c80
[ 753.675209] ? apparmor_task_setrlimit+0x690/0x690
[ 753.680687] ? vma_is_stack_for_current+0xb0/0xb0
[ 753.686073] vfs_read+0x109/0x3e0
[ 753.689900] SyS_read+0xcc/0x1d0
[ 753.693628] ? kernel_write+0x1a0/0x1a0
[ 753.698034] ? trace_hardirqs_on_caller+0x3cb/0x680
[ 753.703610] ? trace_hardirqs_on_thunk+0x1a/0x1c
[ 753.708898] entry_SYSCALL_64_fastpath+0x1c/0xb1
[ 753.714180] RIP: 0033:0x7f62c82296b0
[ 753.718294] RSP: 002b:00007ffc2d6726c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 753.726919] RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007f62c82296b0
[ 753.735028] RDX: 0000000000000400 RSI: 00007f62c8722000 RDI: 0000000000000006
[ 753.743138] RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
[ 753.751246] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000
[ 753.759355] R13: 0000000001d63650 R14: 00007f62c87186a0 R15: 0000000000000028
[ 753.767478]
[ 753.769256] The buggy address belongs to the variable:
[ 753.775125] kprobes_seq_ops+0x1268/0x15c0
[ 753.779820]
[ 753.781595] Memory state around the buggy address:
[ 753.787075] ffffffffa96b9680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 753.795301] ffffffffa96b9700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 753.803526] >ffffffffa96b9780: 07 fa fa fa fa fa fa fa 00 05 fa fa fa fa fa fa
[ 753.811751] ^
[ 753.818105] ffffffffa96b9800: 02 fa fa fa fa fa fa fa 00 00 04 fa fa fa fa fa
[ 753.826330] ffffffffa96b9880: 00 00 00 01 fa fa fa fa 00 00 00 00 01 fa fa fa
[ 753.834554] ==================================================================