==================================================================
BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596
Read of size 4 at addr ffff88806c3a8750 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.3.0-rc3+ #154
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351
 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482
 kasan_report+0x12/0x17 mm/kasan/common.c:612
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
 tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline]
 tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596
 tcp_write_timer+0xa8/0x1e0 net/ipv4/tcp_timer.c:612
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322
 expire_timers kernel/time/timer.c:1366 [inline]
 __run_timers kernel/time/timer.c:1685 [inline]
 __run_timers kernel/time/timer.c:1653 [inline]
 run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:537 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 08 0d 6f fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d e4 93 4a 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d d4 93 4a 00 fb f4 <c3> 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 de c2 22 fa e8 19
RSP: 0018:ffff8880a98dfd68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5e65 RBX: ffff8880a98c6340 RCX: 1ffffffff134b4a6
RDX: dffffc0000000000 RSI: ffffffff817805de RDI: ffffffff873d8a4c
RBP: ffff8880a98dfd98 R08: ffff8880a98c6340 R09: ffffed1015318c69
R10: ffffed1015318c68 R11: ffff8880a98c6347 R12: dffffc0000000000
R13: ffffffff89a57338 R14: 0000000000000000 R15: 0000000000000001
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571
 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x413/0x760 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
 start_secondary+0x315/0x430 arch/x86/kernel/smpboot.c:264
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

Allocated by task 1433:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:487 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:460
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:495
 slab_post_alloc_hook mm/slab.h:520 [inline]
 slab_alloc mm/slab.c:3319 [inline]
 kmem_cache_alloc+0x121/0x710 mm/slab.c:3483
 mempool_alloc_slab+0x47/0x60 mm/mempool.c:513
 mempool_alloc+0x169/0x380 mm/mempool.c:393
 bvec_alloc+0xdd/0x2f0 block/bio.c:206
 bio_alloc_bioset+0x465/0x680 block/bio.c:497
 bio_alloc include/linux/bio.h:400 [inline]
 io_submit_init_bio fs/ext4/page-io.c:366 [inline]
 io_submit_add_bh fs/ext4/page-io.c:391 [inline]
 ext4_bio_write_page+0xe1d/0x1722 fs/ext4/page-io.c:503
 mpage_submit_page+0x15a/0x270 fs/ext4/inode.c:2253
 mpage_process_page_bufs+0x60c/0x720 fs/ext4/inode.c:2364
 mpage_prepare_extent_to_map+0xa05/0xf90 fs/ext4/inode.c:2722
 ext4_writepages+0x998/0x2ec0 fs/ext4/inode.c:2850
 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2342
 __filemap_fdatawrite_range+0x26d/0x340 mm/filemap.c:415
 file_write_and_wait_range+0x9a/0x100 mm/filemap.c:773
 __generic_file_fsync+0x79/0x200 fs/libfs.c:996
 ext4_sync_file+0x89a/0x15c0 fs/ext4/fsync.c:120
 vfs_fsync_range+0x141/0x230 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2799 [inline]
 ext4_file_write_iter+0x839/0x1430 fs/ext4/file.c:281
 call_write_iter include/linux/fs.h:1870 [inline]
 do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:951
 vfs_iter_write+0x77/0xb0 fs/read_write.c:983
 iter_file_splice_write+0x66d/0xbe0 fs/splice.c:746
 do_splice_from fs/splice.c:848 [inline]
 direct_splice_actor+0x123/0x190 fs/splice.c:1020
 splice_direct_to_actor+0x366/0x970 fs/splice.c:975
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1063
 do_sendfile+0x597/0xd00 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1519 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1511
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 10013:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:449
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457
 __cache_free mm/slab.c:3425 [inline]
 kmem_cache_free+0x86/0x320 mm/slab.c:3693
 mempool_free_slab+0x1e/0x30 mm/mempool.c:520
 mempool_free+0xeb/0x370 mm/mempool.c:502
 bvec_free+0xa6/0xc0 block/bio.c:161
 bio_free+0x230/0x420 block/bio.c:247
 bio_put+0xda/0x110 block/bio.c:549
 ext4_end_bio+0x198/0x6d0 fs/ext4/page-io.c:335
 bio_endio+0x611/0xaf0 block/bio.c:1830
 req_bio_endio block/blk-core.c:239 [inline]
 blk_update_request+0x32e/0xc10 block/blk-core.c:1424
 scsi_end_request+0x7f/0x840 drivers/scsi/scsi_lib.c:579
 scsi_io_completion+0x20a/0x1420 drivers/scsi/scsi_lib.c:963
 scsi_finish_command+0x3b7/0x670 drivers/scsi/scsi.c:228
 scsi_softirq_done+0x326/0x3b0 drivers/scsi/scsi_lib.c:1465
 blk_done_softirq+0x2fe/0x4d0 block/blk-softirq.c:37
 __do_softirq+0x262/0x98c kernel/softirq.c:292

The buggy address belongs to the object at ffff88806c3a81c0
 which belongs to the cache biovec-max of size 4096
The buggy address is located 1424 bytes inside of
 4096-byte region [ffff88806c3a81c0, ffff88806c3a91c0)
The buggy address belongs to the page:
page:ffffea0001b0ea00 refcount:1 mapcount:0 mapping:ffff8880a99b0700 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea000265d308 ffffea00023aa388 ffff8880a99b0700
raw: 0000000000000000 ffff88806c3a81c0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88806c3a8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806c3a8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806c3a8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88806c3a8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806c3a8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================