9pnet: Found fid 6 not clunked ================================================================== BUG: KASAN: slab-use-after-free in p9_fid_destroy+0xb5/0xd0 net/9p/client.c:885 Read of size 8 at addr ffff888000d3f200 by task syz-executor.2/7560 CPU: 0 PID: 7560 Comm: syz-executor.2 Not tainted 6.9.0-syzkaller-07726-g3c999d1ae3c7 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 p9_fid_destroy+0xb5/0xd0 net/9p/client.c:885 p9_client_destroy+0x14c/0x480 net/9p/client.c:1071 v9fs_session_close+0x49/0x2d0 fs/9p/v9fs.c:506 v9fs_kill_super+0x4d/0xa0 fs/9p/vfs_super.c:196 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472 deactivate_super+0xde/0x100 fs/super.c:505 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x82/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf725b579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000ff90e688 EFLAGS: 00000292 ORIG_RAX: 0000000000000034 RAX: 0000000000000000 RBX: 00000000ff90e730 RCX: 0000000000000009 RDX: 00000000f73b1ff4 RSI: 00000000f7302361 RDI: 00000000ff90f7d4 RBP: 00000000ff90e730 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7939: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc include/linux/slab.h:628 [inline] kzalloc include/linux/slab.h:749 [inline] p9_fid_create+0x45/0x470 net/9p/client.c:854 p9_client_walk+0xc7/0x550 net/9p/client.c:1155 clone_fid fs/9p/fid.h:23 [inline] v9fs_fid_clone fs/9p/fid.h:33 [inline] v9fs_file_open+0x5b5/0xae0 fs/9p/vfs_file.c:56 do_dentry_open+0x8da/0x18c0 fs/open.c:955 do_open fs/namei.c:3650 [inline] path_openat+0x1dfb/0x2990 fs/namei.c:3807 do_filp_open+0x1dc/0x430 fs/namei.c:3834 do_sys_openat2+0x17a/0x1e0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_compat_sys_openat fs/open.c:1481 [inline] __se_compat_sys_openat fs/open.c:1479 [inline] __ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1479 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 13: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4353 [inline] kfree+0x129/0x3a0 mm/slub.c:4463 p9_client_clunk+0x12a/0x170 net/9p/client.c:1457 p9_fid_put include/net/9p/client.h:280 [inline] v9fs_free_request+0xdc/0x110 fs/9p/vfs_addr.c:138 netfs_free_request+0x22c/0x690 fs/netfs/objects.c:133 netfs_put_request+0x19b/0x1f0 fs/netfs/objects.c:165 netfs_write_collection_worker+0x19d0/0x59e0 fs/netfs/write_collect.c:701 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff888000d3f200 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of freed 96-byte region [ffff888000d3f200, ffff888000d3f260) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xd3f flags: 0x7ff00000000800(slab|node=0|zone=0|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 007ff00000000800 ffff888015442280 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 13, tgid 13 (kworker/u32:1), ts 66167708156, free_ts 66164376422 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534 prep_new_page mm/page_alloc.c:1541 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2190 [inline] allocate_slab mm/slub.c:2353 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2406 ___slab_alloc+0xd28/0x1810 mm/slub.c:3592 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3682 __slab_alloc_node mm/slub.c:3735 [inline] slab_alloc_node mm/slub.c:3908 [inline] kmalloc_trace+0x306/0x340 mm/slub.c:4065 kmalloc include/linux/slab.h:628 [inline] dst_cow_metrics_generic+0x4c/0x1f0 net/core/dst.c:178 dst_metrics_write_ptr include/net/dst.h:133 [inline] dst_metric_set include/net/dst.h:194 [inline] icmp6_dst_alloc+0x370/0x4a0 net/ipv6/route.c:3286 ndisc_send_skb+0x1279/0x1c30 net/ipv6/ndisc.c:489 ndisc_send_rs+0x12b/0x690 net/ipv6/ndisc.c:719 addrconf_dad_completed+0x4a1/0x1060 net/ipv6/addrconf.c:4359 addrconf_dad_work+0x807/0x1500 net/ipv6/addrconf.c:4267 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 page last free pid 13 tgid 13 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487 rcu_do_batch kernel/rcu/tree.c:2535 [inline] rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2809 handle_softirqs+0x216/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Memory state around the buggy address: ffff888000d3f100: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff888000d3f180: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888000d3f200: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888000d3f280: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff888000d3f300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi