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BUG: KASAN: null-ptr-deref in memcpy include/linux/string.h:372 [inline]
BUG: KASAN: null-ptr-deref in build_sit_entries fs/f2fs/segment.c:3289 [inline]
BUG: KASAN: null-ptr-deref in build_segment_manager+0x4fd2/0x7f40 fs/f2fs/segment.c:3564
Write of size 64 at addr           (null) by task syz-executor.0/30539

CPU: 0 PID: 30539 Comm: syz-executor.0 Not tainted 4.14.198-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 kasan_report_error.cold+0x144/0x194 mm/kasan/report.c:349
 kasan_report+0x6f/0x7b mm/kasan/report.c:409
 memcpy+0x35/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:372 [inline]
 build_sit_entries fs/f2fs/segment.c:3289 [inline]
 build_segment_manager+0x4fd2/0x7f40 fs/f2fs/segment.c:3564
 f2fs_fill_super+0x2e21/0x56a0 fs/f2fs/super.c:2581
 mount_bdev+0x2b3/0x360 fs/super.c:1134
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4608fa
RSP: 002b:00007f6cc404fa88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f6cc404fb20 RCX: 00000000004608fa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f6cc404fae0
RBP: 00007f6cc404fae0 R08: 00007f6cc404fb20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020015000
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