Please use ioctl(SG_SUBMIT_V3) instead of write(), See: http://sg.danny.cz/sg/sg_v40.html ================================================================== BUG: KASAN: double-free or invalid-free in slab_free mm/slub.c:3161 [inline] BUG: KASAN: double-free or invalid-free in kfree+0xe5/0x7f0 mm/slub.c:4215 CPU: 1 PID: 15583 Comm: syz-executor.0 Not tainted 5.12.0-rc2-next-20210311-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 kasan_report_invalid_free+0x51/0x80 mm/kasan/report.c:357 ____kasan_slab_free mm/kasan/common.c:340 [inline] __kasan_slab_free+0x118/0x130 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kfree+0xe5/0x7f0 mm/slub.c:4215 scsi_req_free_cmd include/scsi/scsi_request.h:28 [inline] sg_finish_scsi_blk_rq+0x690/0x810 drivers/scsi/sg.c:3224 sg_common_write+0xa07/0xe70 drivers/scsi/sg.c:1132 sg_v3_submit+0x3b1/0x530 drivers/scsi/sg.c:797 sg_write.part.0+0xaf8/0xec0 drivers/scsi/sg.c:660 sg_write+0x87/0x120 drivers/scsi/sg.c:603 do_loop_readv_writev fs/read_write.c:764 [inline] do_loop_readv_writev fs/read_write.c:748 [inline] do_iter_write+0x489/0x670 fs/read_write.c:868 vfs_writev+0x1aa/0x630 fs/read_write.c:939 do_writev+0x139/0x300 fs/read_write.c:982 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465f69 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3daba52188 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 0000000000000002 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fff54225fcf R14: 00007f3daba52300 R15: 0000000000022000 Allocated by task 15583: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] ____kasan_kmalloc mm/kasan/common.c:506 [inline] ____kasan_kmalloc mm/kasan/common.c:465 [inline] __kasan_kmalloc+0x99/0xc0 mm/kasan/common.c:515 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:686 [inline] sg_start_req+0x16f/0x24e0 drivers/scsi/sg.c:3044 sg_common_write+0x5fd/0xe70 drivers/scsi/sg.c:1109 sg_v3_submit+0x3b1/0x530 drivers/scsi/sg.c:797 sg_write.part.0+0xaf8/0xec0 drivers/scsi/sg.c:660 sg_write+0x87/0x120 drivers/scsi/sg.c:603 do_loop_readv_writev fs/read_write.c:764 [inline] do_loop_readv_writev fs/read_write.c:748 [inline] do_iter_write+0x489/0x670 fs/read_write.c:868 vfs_writev+0x1aa/0x630 fs/read_write.c:939 do_writev+0x139/0x300 fs/read_write.c:982 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 15583: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kfree+0xe5/0x7f0 mm/slub.c:4215 sg_start_req+0x1b33/0x24e0 drivers/scsi/sg.c:3106 sg_common_write+0x5fd/0xe70 drivers/scsi/sg.c:1109 sg_v3_submit+0x3b1/0x530 drivers/scsi/sg.c:797 sg_write.part.0+0xaf8/0xec0 drivers/scsi/sg.c:660 sg_write+0x87/0x120 drivers/scsi/sg.c:603 do_loop_readv_writev fs/read_write.c:764 [inline] do_loop_readv_writev fs/read_write.c:748 [inline] do_iter_write+0x489/0x670 fs/read_write.c:868 vfs_writev+0x1aa/0x630 fs/read_write.c:939 do_writev+0x139/0x300 fs/read_write.c:982 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345 __call_rcu kernel/rcu/tree.c:3038 [inline] call_rcu+0xb1/0x750 kernel/rcu/tree.c:3113 fib6_info_release include/net/ip6_fib.h:337 [inline] fib6_info_release include/net/ip6_fib.h:334 [inline] fib6_del_route net/ipv6/ip6_fib.c:1994 [inline] fib6_del+0x11ae/0x15a0 net/ipv6/ip6_fib.c:2027 fib6_clean_node+0x398/0x5c0 net/ipv6/ip6_fib.c:2189 fib6_walk_continue+0x4aa/0x8e0 net/ipv6/ip6_fib.c:2111 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2159 fib6_clean_tree+0xdb/0x120 net/ipv6/ip6_fib.c:2239 __fib6_clean_all+0x120/0x290 net/ipv6/ip6_fib.c:2255 rt6_sync_down_dev net/ipv6/route.c:4768 [inline] rt6_disable_ip+0x77f/0x890 net/ipv6/route.c:4773 addrconf_ifdown.isra.0+0xf6/0x15b0 net/ipv6/addrconf.c:3706 addrconf_notify+0x55c/0x23e0 net/ipv6/addrconf.c:3631 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2063 call_netdevice_notifiers_extack net/core/dev.c:2075 [inline] call_netdevice_notifiers net/core/dev.c:2089 [inline] dev_close_many+0x2ff/0x620 net/core/dev.c:1664 unregister_netdevice_many+0x3ff/0x1770 net/core/dev.c:10883 ip_tunnel_delete_nets+0x3eb/0x5b0 net/ipv4/ip_tunnel.c:1113 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:178 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 The buggy address belongs to the object at ffff888026cda200 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes inside of 256-byte region [ffff888026cda200, ffff888026cda300) The buggy address belongs to the page: page:ffffea00009b3680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26cda head:ffffea00009b3680 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888010841b40 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888026cda100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888026cda180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888026cda200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888026cda280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888026cda300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================