BUG: memory leak
unreferenced object 0xffff888123bc0800 (size 2048):
  comm "syz-executor138", pid 6895, jiffies 4295008131 (age 256.620s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    20 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00   ...............
  backtrace:
    [<0000000001074cef>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
    [<0000000001074cef>] slab_post_alloc_hook mm/slab.h:522 [inline]
    [<0000000001074cef>] slab_alloc mm/slab.c:3319 [inline]
    [<0000000001074cef>] __do_kmalloc mm/slab.c:3653 [inline]
    [<0000000001074cef>] __kmalloc+0x169/0x300 mm/slab.c:3664
    [<00000000bb866f56>] kmalloc include/linux/slab.h:557 [inline]
    [<00000000bb866f56>] bio_alloc_bioset+0x1b8/0x2c0 block/bio.c:440
    [<00000000d90288e9>] bio_kmalloc include/linux/bio.h:405 [inline]
    [<00000000d90288e9>] bio_copy_user_iov+0x112/0x4b0 block/bio.c:1263
    [<00000000b64bd35d>] __blk_rq_map_user_iov block/blk-map.c:73 [inline]
    [<00000000b64bd35d>] blk_rq_map_user_iov+0xc6/0x2b0 block/blk-map.c:142
    [<0000000028c834fd>] blk_rq_map_user+0x71/0xb0 block/blk-map.c:172
    [<000000006614b0fb>] sg_start_req drivers/scsi/sg.c:1813 [inline]
    [<000000006614b0fb>] sg_common_write.isra.0+0x619/0xa10 drivers/scsi/sg.c:809
    [<00000000906f57d1>] sg_write.part.0+0x325/0x570 drivers/scsi/sg.c:709
    [<00000000b9248946>] sg_write+0x44/0x64 drivers/scsi/sg.c:617
    [<0000000084ef23f6>] __vfs_write+0x43/0xa0 fs/read_write.c:494
    [<000000008c9ad3c3>] vfs_write fs/read_write.c:558 [inline]
    [<000000008c9ad3c3>] vfs_write+0xee/0x210 fs/read_write.c:542
    [<00000000f289dca3>] ksys_write+0x7c/0x130 fs/read_write.c:611
    [<00000000408e4570>] __do_sys_write fs/read_write.c:623 [inline]
    [<00000000408e4570>] __se_sys_write fs/read_write.c:620 [inline]
    [<00000000408e4570>] __x64_sys_write+0x1e/0x30 fs/read_write.c:620
    [<00000000b1322188>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296
    [<00000000ef72e0f7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9