KASAN: null-ptr-deref Write in build_segment

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.14	KASAN: null-ptr-deref Write in build_segment_manager				1	1510d	1510d	0/1	auto-closed as invalid on 2021/01/31 08:13
linux-4.14	KASAN: slab-out-of-bounds Read in build_segment_manager f2fs	C		error	5	651d	1508d	0/1	upstream: reported C repro on 2020/10/05 08:04

================================================================== BUG: KASAN: null-ptr-deref in memset include/linux/string.h:361 [inline] BUG: KASAN: null-ptr-deref in build_sit_entries fs/f2fs/segment.c:3286 [inline] BUG: KASAN: null-ptr-deref in build_segment_manager+0x44b1/0x80e0 fs/f2fs/segment.c:3567 Write of size 64 at addr (null) by task syz-executor.0/25825 CPU: 0 PID: 25825 Comm: syz-executor.0 Not tainted 4.14.256-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+0x1b2/0x281 lib/dump_stack.c:58 kasan_report_error.cold+0x144/0x191 mm/kasan/report.c:349 kasan_report+0x6f/0x80 mm/kasan/report.c:409 memset+0x20/0x40 mm/kasan/kasan.c:285 memset include/linux/string.h:361 [inline] build_sit_entries fs/f2fs/segment.c:3286 [inline] build_segment_manager+0x44b1/0x80e0 fs/f2fs/segment.c:3567 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:2572 [inline] do_mount+0xe65/0x2a10 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f7a9db2601a RSP: 002b:00007f7a9ca99fa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f7a9db2601a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f7a9ca9a000 RBP: 00007f7a9ca9a040 R08: 00007f7a9ca9a040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000 R13: 0000000020000100 R14: 00007f7a9ca9a000 R15: 0000000020014b00 ==================================================================