================================================================== BUG: KASAN: stack-out-of-bounds in iov_iter_advance+0x4b3/0x4f0 lib/iov_iter.c:491 Read of size 8 at addr ffff8801aaa97d60 by task syz-executor.3/20345 CPU: 0 PID: 20345 Comm: syz-executor.3 Not tainted 4.4.174+ #4 0000000000000000 cefd38a42635585d ffff8801aaa97a10 ffffffff81aad1a1 0000000000000000 ffffea0006aaa5c0 ffff8801aaa97d60 0000000000000008 ffff8801aaa97d58 ffff8801aaa97a48 ffffffff81490120 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] print_address_description+0x6f/0x21b mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report mm/kasan/report.c:408 [inline] [] kasan_report.cold+0x8c/0x2be mm/kasan/report.c:393 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] iov_iter_advance+0x4b3/0x4f0 lib/iov_iter.c:491 [] tun_get_user+0x2c6/0x2640 drivers/net/tun.c:1124 [] tun_chr_write_iter+0xda/0x190 drivers/net/tun.c:1283 [] new_sync_write fs/read_write.c:480 [inline] [] __vfs_write+0x2e8/0x3d0 fs/read_write.c:493 [] vfs_write+0x182/0x4e0 fs/read_write.c:540 [] SYSC_write fs/read_write.c:587 [inline] [] SyS_write+0xdc/0x1c0 fs/read_write.c:579 [] entry_SYSCALL_64_fastpath+0x1e/0x9a The buggy address belongs to the page: page:ffffea0006aaa5c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x4000000000000000() page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801aaa97c00: f2 f2 f2 f2 f2 00 00 00 00 00 00 00 f3 f3 f3 f3 ffff8801aaa97c80: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8801aaa97d00: 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 00 00 00 ^ ffff8801aaa97d80: 00 00 f2 f2 f2 f2 f2 00 00 00 00 00 f3 f3 f3 f3 ffff8801aaa97e00: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================