ci2 starts bisection 2024-08-18 19:28:24.643679358 +0000 UTC m=+155974.259111756 bisecting fixing commit since fa74641fb6b93a19ccb50579886ecc98320230f9 building syzkaller on 4bce1a3e705a8b62de8194bdb28f5eef89c8feec ensuring issue is reproducible on original commit fa74641fb6b93a19ccb50579886ecc98320230f9 testing commit fa74641fb6b93a19ccb50579886ecc98320230f9 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 12ac45819a6cb25031743afd9a1293ad269d953c4e5bef55849f0d5d9d321139 run #0: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #10: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #11: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #12: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #13: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #14: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #15: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #16: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #17: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #18: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #19: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock representative crash: KASAN: use-after-free Read in ext4_convert_inline_data_nolock, types: [KASAN] check whether we can drop unnecessary instrumentation disabling configs for [ATOMIC_SLEEP HANG LEAK UBSAN BUG LOCKDEP], they are not needed testing commit fa74641fb6b93a19ccb50579886ecc98320230f9 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: fa63c129a933b2f4e97b697c073f996b21801485e38589f736e5fb2c9bdb755f run #0: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock representative crash: KASAN: use-after-free Read in ext4_convert_inline_data_nolock, types: [KASAN] the bug reproduces without the instrumentation disabling configs for [LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP HANG], they are not needed kconfig minimization: base=3822 full=7524 leaves diff=1993 split chunks (needed=false): <1993> split chunk #0 of len 1993 into 5 parts testing without sub-chunk 1/5 disabling configs for [LOCKDEP ATOMIC_SLEEP HANG LEAK UBSAN BUG], they are not needed testing commit fa74641fb6b93a19ccb50579886ecc98320230f9 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: b13eed145bf1692d528a82ce5474cc1ca11caa49fe88d784ef57d0130d86b81f run #0: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock representative crash: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock, 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 fa74641fb6b93a19ccb50579886ecc98320230f9 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 840af0981e646407d39d84c821e0275dd938bf2b23aa7bc9693fd786a123d94d run #0: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock representative crash: KASAN: use-after-free Read in ext4_convert_inline_data_nolock, types: [KASAN] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [UBSAN BUG LOCKDEP ATOMIC_SLEEP HANG LEAK], they are not needed testing commit fa74641fb6b93a19ccb50579886ecc98320230f9 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 8ac4719f301b43bab57d1ffd4af5329b547db635a701ee35e85983397c823e71 run #0: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock representative crash: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock, types: [KASAN] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing commit fa74641fb6b93a19ccb50579886ecc98320230f9 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 266024cb9327e04e7e9819a2071069b959b8b986a83b5c5c7d621bae1cdff4f5 run #0: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock representative crash: KASAN: use-after-free Read in ext4_convert_inline_data_nolock, types: [KASAN] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [BUG LOCKDEP ATOMIC_SLEEP HANG LEAK UBSAN], they are not needed testing commit fa74641fb6b93a19ccb50579886ecc98320230f9 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: e972dd94a8a28a5755c20e3faa738e09e50b13e3d165a3d5153d1c31200a910a run #0: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock representative crash: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock, types: [KASAN] the chunk can be dropped disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing current HEAD 117ac406ba904da738fb79a3b2c96d4a385292c1 testing commit 117ac406ba904da738fb79a3b2c96d4a385292c1 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 08de6c78b006ca8ff38be53f5bdea451687345c7a7e5d28ec511f94e68c6dfcf run #0: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #1: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #2: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #3: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #4: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #5: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #6: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #7: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock run #8: crashed: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock run #9: crashed: KASAN: use-after-free Read in ext4_convert_inline_data_nolock representative crash: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock, types: [KASAN] crash still not fixed/happens on the oldest tested release revisions tested: 8, total time: 1h16m30.732748937s (build: 37m19.942889404s, test: 33m59.880288702s) crash still not fixed or there were kernel test errors commit msg: Linux 6.1.105 crash: KASAN: slab-out-of-bounds Read in ext4_convert_inline_data_nolock loop0: detected capacity change from 0 to 2048 EXT4-fs (loop0): mounted filesystem without journal. Quota mode: none. ================================================================== BUG: KASAN: slab-out-of-bounds in ext4_read_inline_data fs/ext4/inline.c:210 [inline] BUG: KASAN: slab-out-of-bounds in ext4_convert_inline_data_nolock+0x282/0xc10 fs/ext4/inline.c:1216 Read of size 20 at addr ffff888116b491a3 by task syz-executor.0/1401 CPU: 0 PID: 1401 Comm: syz-executor.0 Not tainted 6.1.105-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xf4/0x251 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 kasan_check_range+0x27f/0x290 mm/kasan/generic.c:189 memcpy+0x25/0x60 mm/kasan/shadow.c:65 ext4_read_inline_data fs/ext4/inline.c:210 [inline] ext4_convert_inline_data_nolock+0x282/0xc10 fs/ext4/inline.c:1216 ext4_convert_inline_data+0x3b8/0x4d0 fs/ext4/inline.c:2081 ext4_fallocate+0x136/0x1790 fs/ext4/extents.c:4732 vfs_fallocate+0x30c/0x3d0 fs/open.c:323 ksys_fallocate fs/open.c:346 [inline] __do_sys_fallocate fs/open.c:354 [inline] __se_sys_fallocate fs/open.c:352 [inline] __x64_sys_fallocate+0xa6/0xd0 fs/open.c:352 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7effd414f959 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:00007effd3cd20c8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007effd426ef80 RCX: 00007effd414f959 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007effd41abc88 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000006 R14: 00007effd426ef80 R15: 00007ffddafd18b8 Allocated by task 1394: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x54/0x3e0 mm/slab.h:737 kmem_cache_alloc_bulk+0x2d4/0x360 mm/slub.c:3854 mt_alloc_bulk lib/maple_tree.c:157 [inline] mas_alloc_nodes+0x359/0x680 lib/maple_tree.c:1299 mas_node_count_gfp lib/maple_tree.c:1359 [inline] mas_preallocate+0xee/0x290 lib/maple_tree.c:5804 __vma_adjust+0x31c/0x12b0 mm/mmap.c:724 __split_vma+0x32f/0x4a0 do_mas_align_munmap+0xd67/0x11e0 mm/mmap.c:2491 do_mas_munmap+0x195/0x1f0 mm/mmap.c:2640 mmap_region+0x708/0x1780 mm/mmap.c:2688 do_mmap+0x69e/0xb60 mm/mmap.c:1425 vm_mmap_pgoff+0x1b7/0x280 mm/util.c:520 ksys_mmap_pgoff+0x2cf/0x3b0 mm/mmap.c:1471 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 1394: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x122/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] kmem_cache_free_bulk+0x582/0x770 mm/slub.c:3779 mt_free_bulk lib/maple_tree.c:162 [inline] mas_destroy+0x2730/0x2ec0 lib/maple_tree.c:5858 mas_store_prealloc+0x283/0x3b0 lib/maple_tree.c:5788 __vma_adjust+0xc22/0x12b0 mm/mmap.c:797 __split_vma+0x32f/0x4a0 do_mas_align_munmap+0xd67/0x11e0 mm/mmap.c:2491 do_mas_munmap+0x195/0x1f0 mm/mmap.c:2640 mmap_region+0x708/0x1780 mm/mmap.c:2688 do_mmap+0x69e/0xb60 mm/mmap.c:1425 vm_mmap_pgoff+0x1b7/0x280 mm/util.c:520 ksys_mmap_pgoff+0x2cf/0x3b0 mm/mmap.c:1471 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888116b49000 which belongs to the cache maple_node of size 256 The buggy address is located 163 bytes to the right of 256-byte region [ffff888116b49000, ffff888116b49100) The buggy address belongs to the physical page: page:ffffea00045ad200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888116b48a00 pfn:0x116b48 head:ffffea00045ad200 order:1 compound_mapcount:0 compound_pincount:0 flags: 0x200000000010200(slab|head|node=0|zone=2) raw: 0200000000010200 ffffea00045bd788 ffffea000453e988 ffff8881000cd000 raw: ffff888116b48a00 000000000010000d 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 837, tgid 837 (modprobe), ts 34921588473, free_ts 34910541524 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x286/0x2b0 mm/page_alloc.c:2517 prep_new_page mm/page_alloc.c:2524 [inline] get_page_from_freelist+0x2ba7/0x2de0 mm/page_alloc.c:4290 __alloc_pages+0x251/0x640 mm/page_alloc.c:5558 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x70/0x250 mm/slub.c:1992 ___slab_alloc+0x9df/0xe70 mm/slub.c:3180 kmem_cache_alloc_bulk+0x15c/0x360 mm/slub.c:3830 mt_alloc_bulk lib/maple_tree.c:157 [inline] mas_alloc_nodes+0x359/0x680 lib/maple_tree.c:1299 mas_node_count_gfp lib/maple_tree.c:1359 [inline] mas_preallocate+0xee/0x290 lib/maple_tree.c:5804 __vma_adjust+0x31c/0x12b0 mm/mmap.c:724 __split_vma+0x32f/0x4a0 mprotect_fixup+0x5b5/0x630 mm/mprotect.c:623 do_mprotect_pkey+0x6e1/0x930 mm/mprotect.c:792 __do_sys_mprotect mm/mprotect.c:819 [inline] __se_sys_mprotect mm/mprotect.c:816 [inline] __x64_sys_mprotect+0x77/0x90 mm/mprotect.c:816 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1444 [inline] free_pcp_prepare mm/page_alloc.c:1494 [inline] free_unref_page_prepare+0xccc/0xdb0 mm/page_alloc.c:3369 free_unref_page+0x30/0x230 mm/page_alloc.c:3464 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1af/0x210 mm/slub.c:2586 put_cpu_partial+0x150/0x1a0 mm/slub.c:2662 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x54/0x3e0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x10c/0x290 mm/slub.c:3422 getname_flags+0x9c/0x430 fs/namei.c:139 vfs_fstatat fs/stat.c:266 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat+0xd7/0x790 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff888116b49080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888116b49100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888116b49180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888116b49200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888116b49280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================