================================================================== 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 ffff8880a5f52610 by task kworker/u4:1/21 CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.3.0-rc5+ #170 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __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 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:337 do_softirq kernel/softirq.c:329 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:189 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x31/0x40 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:383 [inline] del_nbp+0x140/0xc60 net/bridge/br_if.c:334 br_dev_delete+0x9c/0x1a0 net/bridge/br_if.c:373 default_device_exit_batch+0x25c/0x410 net/core/dev.c:9775 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:175 cleanup_net+0x4e2/0xa60 net/core/net_namespace.c:594 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 15393: 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 __writeback_single_inode+0x136/0x13f0 fs/fs-writeback.c:1364 writeback_sb_inodes+0x596/0xf20 fs/fs-writeback.c:1628 __writeback_inodes_wb+0xc3/0x260 fs/fs-writeback.c:1697 wb_writeback+0x910/0xd90 fs/fs-writeback.c:1806 wb_check_background_flush fs/fs-writeback.c:1874 [inline] wb_do_writeback fs/fs-writeback.c:1962 [inline] wb_workfn+0xa90/0x1230 fs/fs-writeback.c:1990 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 9686: 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 ffff8880a5f52180 which belongs to the cache biovec-max of size 4096 The buggy address is located 1168 bytes inside of 4096-byte region [ffff8880a5f52180, ffff8880a5f53180) The buggy address belongs to the page: page:ffffea000297d480 refcount:1 mapcount:0 mapping:ffff88821b25a700 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001b50a08 ffffea00023b9408 ffff88821b25a700 raw: 0000000000000000 ffff8880a5f52180 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a5f52500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a5f52580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a5f52600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a5f52680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a5f52700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================