ci2 starts bisection 2023-12-13 20:08:34.518148334 +0000 UTC m=+3077.506725143 bisecting fixing commit since 61cfd264993d07540f60a5c53d77a14c818e54a9 building syzkaller on 6d6dbf8ab21a52df701946afac2a86f93a88fdc8 ensuring issue is reproducible on original commit 61cfd264993d07540f60a5c53d77a14c818e54a9 testing commit 61cfd264993d07540f60a5c53d77a14c818e54a9 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 7861df0d7c1f1eccbbed9ca492f77e3ab49e914debeac7133578846f06d14b98 run #0: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #1: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #2: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #3: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #4: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #5: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #6: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #7: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #8: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #9: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #10: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #11: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #12: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #13: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #14: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #15: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #16: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #17: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #18: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #19: crashed: KASAN: use-after-free Read in unix_stream_read_actor representative crash: KASAN: use-after-free Read in unix_stream_read_actor, types: [KASAN] check whether we can drop unnecessary instrumentation disabling configs for [LOCKDEP ATOMIC_SLEEP HANG LEAK UBSAN BUG], they are not needed testing commit 61cfd264993d07540f60a5c53d77a14c818e54a9 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 85708d0188afdd401801d47009f9806580c8e06cc25160a083bd59e7293205eb run #0: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #1: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #2: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #3: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #4: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #5: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #6: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #7: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #8: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #9: crashed: KASAN: use-after-free Read in __skb_datagram_iter representative crash: KASAN: use-after-free Read in __skb_datagram_iter, types: [KASAN] the bug reproduces without the instrumentation disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed kconfig minimization: base=4920 full=6161 leaves diff=241 split chunks (needed=false): <241> split chunk #0 of len 241 into 5 parts testing without sub-chunk 1/5 disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 61cfd264993d07540f60a5c53d77a14c818e54a9 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 5743f950168f1c86488ed39e658dfe9be0d8749b2584321ef15da7f1704faff9 run #0: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #1: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #2: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #3: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #4: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #5: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #6: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #7: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #8: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #9: crashed: KASAN: use-after-free Read in unix_stream_read_actor representative crash: KASAN: use-after-free Read in unix_stream_read_actor, types: [KASAN] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP HANG], they are not needed testing commit 61cfd264993d07540f60a5c53d77a14c818e54a9 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: c70f7e6924817e6d0b0f96d44abee25f79ced762b62cca17c43742db00c211dc run #0: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #1: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #2: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #3: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #4: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #5: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #6: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #7: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #8: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #9: crashed: KASAN: use-after-free Read in unix_stream_read_actor representative crash: KASAN: use-after-free Read in unix_stream_read_actor, types: [KASAN] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 61cfd264993d07540f60a5c53d77a14c818e54a9 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 9e4d9ec877efc48775734f99a5c4828e4e54d697b164efa5031dbf641ecc1990 run #0: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #1: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #2: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #3: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #4: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #5: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #6: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #7: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #8: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #9: crashed: KASAN: use-after-free Read in unix_stream_read_actor representative crash: KASAN: use-after-free Read in unix_stream_read_actor, types: [KASAN] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [UBSAN BUG LOCKDEP ATOMIC_SLEEP HANG LEAK], they are not needed testing commit 61cfd264993d07540f60a5c53d77a14c818e54a9 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 5d090807622c85344fdcde9a2483d8835084d508d79696576609e1e0ed550064 run #0: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #1: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #2: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #3: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #4: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #5: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #6: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #7: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #8: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #9: crashed: KASAN: use-after-free Read in unix_stream_read_actor representative crash: KASAN: use-after-free Read in __skb_datagram_iter, types: [KASAN] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 61cfd264993d07540f60a5c53d77a14c818e54a9 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 failed building 61cfd264993d07540f60a5c53d77a14c818e54a9: net/socket.c:1189: undefined reference to `wext_handle_ioctl' net/socket.c:3383: undefined reference to `compat_wext_handle_ioctl' net/core/net-procfs.c:343: undefined reference to `wext_proc_exit' net/core/net-procfs.c:327: undefined reference to `wext_proc_init' minimized to 45 configs; suspects: [HID_ZEROPLUS USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD USB_OHCI_HCD_PCI USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_PRINTER USB_SERIAL USB_SERIAL_FTDI_SIO USB_SERIAL_GENERIC USB_SERIAL_PL2303 USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_TRANCEVIBRATOR USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_WDM WLAN WLAN_VENDOR_ATH WLAN_VENDOR_ATMEL WLAN_VENDOR_BROADCOM WLAN_VENDOR_INTERSIL WLAN_VENDOR_MARVELL WLAN_VENDOR_MEDIATEK WLAN_VENDOR_MICROCHIP WLAN_VENDOR_RALINK WLAN_VENDOR_REALTEK WLAN_VENDOR_RSI WLAN_VENDOR_ZYDAS X86_X32 ZEROPLUS_FF] disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing current HEAD 05ef4ccb57746f921003b9340fc2f0532c177f41 testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 832764362da087470977b60911f7883ff4d47dcb6975d68ce0134d7fddeedc4d run #0: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #1: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #2: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #3: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #4: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #5: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #6: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #7: crashed: KASAN: use-after-free Read in unix_stream_read_actor run #8: crashed: KASAN: use-after-free Read in __skb_datagram_iter run #9: crashed: KASAN: use-after-free Read in unix_stream_read_actor representative crash: KASAN: use-after-free Read in unix_stream_read_actor, types: [KASAN] crash still not fixed/happens on the oldest tested release revisions tested: 7, total time: 48m19.842932385s (build: 15m2.364890344s, test: 31m16.962647678s) crash still not fixed or there were kernel test errors commit msg: Revert "ipvlan: properly track tx_errors" crash: KASAN: use-after-free Read in unix_stream_read_actor ================================================================== BUG: KASAN: use-after-free in unix_stream_read_actor+0x87/0xb0 net/unix/af_unix.c:2809 Read of size 4 at addr ffff88810d32b2c4 by task syz-executor.4/854 CPU: 0 PID: 854 Comm: syz-executor.4 Not tainted 5.15.139-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x38/0x49 lib/dump_stack.c:106 print_address_description.constprop.0+0x24/0x160 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report.cold+0x82/0xdb mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 unix_stream_read_actor+0x87/0xb0 net/unix/af_unix.c:2809 unix_stream_recv_urg net/unix/af_unix.c:2535 [inline] unix_stream_read_generic+0x14d4/0x1eb0 net/unix/af_unix.c:2615 unix_stream_recvmsg+0x166/0x210 net/unix/af_unix.c:2847 sock_recvmsg_nosec net/socket.c:964 [inline] sock_recvmsg net/socket.c:982 [inline] sock_recvmsg net/socket.c:978 [inline] ____sys_recvmsg+0x286/0x700 net/socket.c:2648 ___sys_recvmsg+0x109/0x1d0 net/socket.c:2690 __sys_recvmsg+0xc0/0x160 net/socket.c:2720 __do_sys_recvmsg net/socket.c:2730 [inline] __se_sys_recvmsg net/socket.c:2727 [inline] __x64_sys_recvmsg+0x73/0xb0 net/socket.c:2727 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f1b7bc43ae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1b7b7840c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007f1b7bd63120 RCX: 00007f1b7bc43ae9 RDX: 0000000040010083 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 00007f1b7bc8f47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f1b7bd63120 R15: 00007ffd2a739ea8 Allocated by task 853: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] __kasan_slab_alloc+0x94/0xc0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook mm/slab.h:550 [inline] slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3248 [inline] kmem_cache_alloc+0x197/0x480 mm/slub.c:3253 kmem_cache_alloc_node include/linux/slab.h:474 [inline] __alloc_skb+0x14b/0x250 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] alloc_skb_with_frags+0x76/0x4a0 net/core/skbuff.c:6156 sock_alloc_send_pskb+0x68b/0x840 net/core/sock.c:2518 sock_alloc_send_skb+0x13/0x20 net/core/sock.c:2535 queue_oob net/unix/af_unix.c:1980 [inline] unix_stream_sendmsg+0x888/0xcc0 net/unix/af_unix.c:2117 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg+0xb5/0xf0 net/socket.c:716 ____sys_sendmsg+0x694/0x990 net/socket.c:2429 ___sys_sendmsg+0xfc/0x190 net/socket.c:2483 __sys_sendmsg+0xc3/0x160 net/socket.c:2512 __do_sys_sendmsg net/socket.c:2521 [inline] __se_sys_sendmsg net/socket.c:2519 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2519 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 853: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track+0x25/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x24/0x40 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:365 [inline] ____kasan_slab_free mm/kasan/common.c:327 [inline] __kasan_slab_free+0x111/0x150 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x94/0x1a0 mm/slub.c:1749 slab_free mm/slub.c:3519 [inline] kmem_cache_free+0x105/0x250 mm/slub.c:3535 kfree_skbmem+0x95/0x140 net/core/skbuff.c:701 __kfree_skb net/core/skbuff.c:758 [inline] consume_skb net/core/skbuff.c:930 [inline] consume_skb+0xab/0x1d0 net/core/skbuff.c:924 queue_oob net/unix/af_unix.c:2011 [inline] unix_stream_sendmsg+0x9e6/0xcc0 net/unix/af_unix.c:2117 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg+0xb5/0xf0 net/socket.c:716 ____sys_sendmsg+0x694/0x990 net/socket.c:2429 ___sys_sendmsg+0xfc/0x190 net/socket.c:2483 __sys_sendmsg+0xc3/0x160 net/socket.c:2512 __do_sys_sendmsg net/socket.c:2521 [inline] __se_sys_sendmsg net/socket.c:2519 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2519 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88810d32b280 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 68 bytes inside of 240-byte region [ffff88810d32b280, ffff88810d32b370) The buggy address belongs to the page: page:ffffea000434cac0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d32b flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881002faa80 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 853, ts 49792665579, free_ts 49741766568 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook mm/page_alloc.c:2604 [inline] prep_new_page+0x1a2/0x310 mm/page_alloc.c:2610 get_page_from_freelist+0x1ce2/0x30a0 mm/page_alloc.c:4484 __alloc_pages+0x23f/0x2400 mm/page_alloc.c:5776 __alloc_pages_node include/linux/gfp.h:591 [inline] alloc_pages_node include/linux/gfp.h:605 [inline] alloc_pages include/linux/gfp.h:618 [inline] alloc_slab_page mm/slub.c:1793 [inline] allocate_slab+0x39d/0x530 mm/slub.c:1932 new_slab mm/slub.c:1995 [inline] ___slab_alloc.constprop.0+0x3ca/0x890 mm/slub.c:3028 __slab_alloc.constprop.0+0x42/0x80 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3248 [inline] kmem_cache_alloc+0x440/0x480 mm/slub.c:3253 kmem_cache_alloc_node include/linux/slab.h:474 [inline] __alloc_skb+0x14b/0x250 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] alloc_skb_with_frags+0x76/0x4a0 net/core/skbuff.c:6156 sock_alloc_send_pskb+0x68b/0x840 net/core/sock.c:2518 sock_alloc_send_skb+0x13/0x20 net/core/sock.c:2535 queue_oob net/unix/af_unix.c:1980 [inline] unix_stream_sendmsg+0x888/0xcc0 net/unix/af_unix.c:2117 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg+0xb5/0xf0 net/socket.c:716 ____sys_sendmsg+0x694/0x990 net/socket.c:2429 ___sys_sendmsg+0xfc/0x190 net/socket.c:2483 __sys_sendmsg+0xc3/0x160 net/socket.c:2512 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1471 [inline] free_pcp_prepare+0x1b6/0x4c0 mm/page_alloc.c:1543 free_unref_page_prepare mm/page_alloc.c:3533 [inline] free_unref_page+0x84/0x760 mm/page_alloc.c:3615 free_the_page mm/page_alloc.c:804 [inline] __free_pages+0xd7/0xf0 mm/page_alloc.c:5852 __free_slab+0xdb/0x1c0 mm/slub.c:2020 free_slab mm/slub.c:2035 [inline] discard_slab+0x2b/0x40 mm/slub.c:2041 __unfreeze_partials+0x1e2/0x230 mm/slub.c:2527 put_cpu_partial+0x96/0xb0 mm/slub.c:2607 __slab_free+0x21e/0x4d0 mm/slub.c:3388 do_slab_free mm/slub.c:3507 [inline] ___cache_free+0x1ee/0x230 mm/slub.c:3526 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6e/0x150 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x15f/0x1c0 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xaa/0xc0 mm/kasan/common.c:443 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook mm/slab.h:550 [inline] slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3248 [inline] kmem_cache_alloc+0x197/0x480 mm/slub.c:3253 getname_flags.part.0+0x4d/0x480 fs/namei.c:138 getname_flags+0x7d/0xd0 include/linux/audit.h:319 user_path_at_empty+0x23/0x60 fs/namei.c:2852 Memory state around the buggy address: ffff88810d32b180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810d32b200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff88810d32b280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810d32b300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff88810d32b380: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================