================================================================== BUG: KASAN: use-after-free in relay_switch_subbuf+0x8be/0x920 kernel/relay.c:755 Read of size 8 at addr ffff888091489e98 by task syz-executor.3/15143 CPU: 1 PID: 15143 Comm: syz-executor.3 Not tainted 5.2.0-rc5+ #38 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 relay_switch_subbuf+0x8be/0x920 kernel/relay.c:755 relay_reserve include/linux/relay.h:261 [inline] trace_note.isra.0+0x5b8/0x6e0 kernel/trace/blktrace.c:93 trace_note_tsk kernel/trace/blktrace.c:124 [inline] __blk_add_trace+0xb70/0xe10 kernel/trace/blktrace.c:264 blk_add_trace_rq+0x185/0x1f0 kernel/trace/blktrace.c:819 blk_add_trace_rq_complete+0x17a/0x1e0 kernel/trace/blktrace.c:848 trace_block_rq_complete include/trace/events/block.h:116 [inline] blk_update_request+0x80f/0xba0 block/blk-core.c:1369 scsi_end_request+0x7f/0x840 drivers/scsi/scsi_lib.c:565 scsi_io_completion+0x20a/0x1420 drivers/scsi/scsi_lib.c:949 scsi_finish_command+0x3b7/0x670 drivers/scsi/scsi.c:233 scsi_softirq_done+0x33b/0x3e0 drivers/scsi/scsi_lib.c:1449 blk_done_softirq+0x2fe/0x4d0 block/blk-softirq.c:37 __do_softirq+0x25c/0x94c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] do_IRQ+0x10f/0x1d0 arch/x86/kernel/irq.c:259 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:583 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline] RIP: 0010:console_unlock+0xb7c/0xec0 kernel/printk/printk.c:2471 Code: b2 88 48 c1 e8 03 42 80 3c 30 00 0f 85 e4 02 00 00 48 83 3d 05 fd 57 07 00 0f 84 91 01 00 00 e8 3a 4a 16 00 48 8b 7d 98 57 9d <0f> 1f 44 00 00 e9 6d ff ff ff e8 25 4a 16 00 48 8b 7d 08 c7 05 67 RSP: 0018:ffff888049ff7108 EFLAGS: 00000212 ORIG_RAX: ffffffffffffffdd RAX: 0000000000040000 RBX: 0000000000000200 RCX: ffffc9000c43c000 RDX: 0000000000008c5c RSI: ffffffff815a76f6 RDI: 0000000000000212 RBP: ffff888049ff7190 R08: ffff888044530300 R09: ffff888044530bc8 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff842617b0 R14: dffffc0000000000 R15: ffffffff891a0eb0 vprintk_emit+0x2a0/0x700 kernel/printk/printk.c:1986 vprintk_default+0x28/0x30 kernel/printk/printk.c:2013 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:386 printk+0xba/0xed kernel/printk/printk.c:2046 __nla_validate_parse.cold+0x24/0x60 lib/nlattr.c:393 __nla_parse+0x43/0x60 lib/nlattr.c:478 __nlmsg_parse include/net/netlink.h:662 [inline] nlmsg_parse_deprecated include/net/netlink.h:703 [inline] rtnl_dellink+0x14c/0x970 net/core/rtnetlink.c:2823 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5214 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2482 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5232 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline] netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1333 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1922 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:665 ___sys_sendmsg+0x803/0x920 net/socket.c:2286 __sys_sendmsg+0x105/0x1d0 net/socket.c:2324 __do_sys_sendmsg net/socket.c:2333 [inline] __se_sys_sendmsg net/socket.c:2331 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2331 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6d464a6c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004592c9 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6d464a76d4 R13: 00000000004c691a R14: 00000000004db900 R15: 00000000ffffffff Allocated by task 8876: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:437 [inline] slab_alloc mm/slab.c:3326 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488 __d_alloc+0x2e/0x8c0 fs/dcache.c:1622 d_alloc_pseudo+0x1e/0x70 fs/dcache.c:1751 alloc_file_pseudo+0xe2/0x280 fs/file_table.c:225 sock_alloc_file+0x4d/0x170 net/socket.c:408 sock_map_fd net/socket.c:431 [inline] __sys_socket+0x150/0x220 net/socket.c:1521 __do_sys_socket net/socket.c:1526 [inline] __se_sys_socket net/socket.c:1524 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1524 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8876: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3698 __d_free fs/dcache.c:271 [inline] dentry_free+0xed/0x170 fs/dcache.c:348 __dentry_kill+0x457/0x600 fs/dcache.c:593 dentry_kill+0xd7/0x5e0 fs/dcache.c:698 dput+0x570/0x690 fs/dcache.c:859 __fput+0x424/0x890 fs/file_table.c:293 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:185 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888091489e40 which belongs to the cache dentry(87:syz5) of size 288 The buggy address is located 88 bytes inside of 288-byte region [ffff888091489e40, ffff888091489f60) The buggy address belongs to the page: page:ffffea0002452240 refcount:1 mapcount:0 mapping:ffff88808b7efc80 index:0xffff888091489a20 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00024e3f08 ffffea0002456ec8 ffff88808b7efc80 raw: ffff888091489a20 ffff888091489080 0000000100000001 ffff8880893a8800 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8880893a8800 Memory state around the buggy address: ffff888091489d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888091489e00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff888091489e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888091489f00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888091489f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================