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 nobh option
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:840 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xaea/0xcc0 fs/ext4/extents.c:956
Read of size 4 at addr ffff888050683c70 by task syz.0.0/5329

CPU: 0 UID: 0 PID: 5329 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:840 [inline]
 ext4_find_extent+0xaea/0xcc0 fs/ext4/extents.c:956
 ext4_ext_map_blocks+0x283/0x58b0 fs/ext4/extents.c:4261
 ext4_map_create_blocks+0x11d/0x540 fs/ext4/inode.c:616
 ext4_map_blocks+0x7cd/0x11d0 fs/ext4/inode.c:809
 mpage_map_one_extent fs/ext4/inode.c:2373 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2467 [inline]
 ext4_do_writepages+0x22c0/0x46e0 fs/ext4/inode.c:2925
 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3019
 do_writepages+0x32e/0x550 mm/page-writeback.c:2554
 filemap_writeback mm/filemap.c:387 [inline]
 filemap_fdatawrite_range mm/filemap.c:412 [inline]
 file_write_and_wait_range+0x36e/0x440 mm/filemap.c:786
 generic_buffers_fsync_noflush+0x70/0x1d0 fs/buffer.c:606
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x321/0xb70 fs/ext4/fsync.c:147
 generic_write_sync include/linux/fs.h:2640 [inline]
 ext4_buffered_write_iter+0x2ca/0x3a0 fs/ext4/file.c:306
 ext4_file_write_iter+0x298/0x1bf0 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:688
 ksys_pwrite64 fs/read_write.c:795 [inline]
 __do_sys_pwrite64 fs/read_write.c:803 [inline]
 __se_sys_pwrite64 fs/read_write.c:800 [inline]
 __x64_sys_pwrite64+0x199/0x230 fs/read_write.c:800
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93ba79c799
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:00007f93bb56dfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f93baa15fa0 RCX: 00007f93ba79c799
RDX: 000000000000fdef RSI: 0000200000000140 RDI: 0000000000000007
RBP: 00007f93ba832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fecc R11: 0000000000000246 R12: 0000000000000000
R13: 00007f93baa16038 R14: 00007f93baa15fa0 R15: 00007ffc94396518
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x50683
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea000141a108 ffffea000141a088 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:
 ffff888050683b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888050683b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888050683c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                             ^
 ffff888050683c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888050683d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================