loop0: detected capacity change from 0 to 1024
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
EXT4-fs: Ignoring removed oldalloc option
EXT4-fs: Ignoring removed orlov option
EXT4-fs (loop0): stripe (2) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
==================================================================
BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:841 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xae6/0xcc0 fs/ext4/extents.c:956
Read of size 4 at addr ffff888057119794 by task syz.0.0/5341

CPU: 0 UID: 0 PID: 5341 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 ext4_ext_binsearch fs/ext4/extents.c:841 [inline]
 ext4_find_extent+0xae6/0xcc0 fs/ext4/extents.c:956
 ext4_ext_map_blocks+0x29d/0x6b80 fs/ext4/extents.c:4208
 ext4_map_create_blocks fs/ext4/inode.c:613 [inline]
 ext4_map_blocks+0x8da/0x1830 fs/ext4/inode.c:816
 _ext4_get_block+0x1e3/0x470 fs/ext4/inode.c:916
 ext4_get_block_unwritten+0x2e/0x100 fs/ext4/inode.c:949
 ext4_block_write_begin+0xb14/0x1950 fs/ext4/inode.c:1203
 ext4_write_begin+0xb40/0x1870 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x355/0xd30 fs/ext4/inode.c:3130
 generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4314
 ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299
 ext4_file_write_iter+0x298/0x1c10 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:686
 ksys_write+0x150/0x270 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f700eb9acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f700fb1c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f700ee15fa0 RCX: 00007f700eb9acb9
RDX: 00000000fffffdef RSI: 00002000000000c0 RDI: 000000000000000a
RBP: 00007f700ec08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f700ee16038 R14: 00007f700ee15fa0 R15: 00007ffe90b5f858
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x57119
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00015c4688 ffffea00015c4608 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffff888057119680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888057119700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888057119780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                         ^
 ffff888057119800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888057119880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================