================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline] BUG: KASAN: slab-use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline] BUG: KASAN: slab-use-after-free in __refcount_sub_and_test include/linux/refcount.h:264 [inline] BUG: KASAN: slab-use-after-free in __refcount_dec_and_test include/linux/refcount.h:307 [inline] BUG: KASAN: slab-use-after-free in refcount_dec_and_test include/linux/refcount.h:325 [inline] BUG: KASAN: slab-use-after-free in p9_fid_put include/net/9p/client.h:277 [inline] BUG: KASAN: slab-use-after-free in v9fs_free_request+0x7d/0x110 fs/9p/vfs_addr.c:138 Write of size 4 at addr ffff88800068420c by task kworker/u32:5/1086 CPU: 2 PID: 1086 Comm: kworker/u32:5 Not tainted 6.10.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: events_unbound netfs_write_collection_worker 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 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline] __refcount_sub_and_test include/linux/refcount.h:264 [inline] __refcount_dec_and_test include/linux/refcount.h:307 [inline] refcount_dec_and_test include/linux/refcount.h:325 [inline] p9_fid_put include/net/9p/client.h:277 [inline] v9fs_free_request+0x7d/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 Allocated by task 9680: 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_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [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+0x910/0x1930 fs/open.c:955 do_open fs/namei.c:3650 [inline] path_openat+0x1e3a/0x29f0 fs/namei.c:3807 do_filp_open+0x1dc/0x430 fs/namei.c:3834 do_sys_openat2+0x17a/0x1e0 fs/open.c:1405 do_sys_open fs/open.c:1420 [inline] __do_compat_sys_openat fs/open.c:1480 [inline] __se_compat_sys_openat fs/open.c:1478 [inline] __ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1478 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 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 9168: 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+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2195 [inline] slab_free mm/slub.c:4436 [inline] kfree+0x12a/0x3b0 mm/slub.c:4557 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:473 deactivate_super+0xde/0x100 fs/super.c:506 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+0x80/0x120 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 The buggy address belongs to the object at ffff888000684200 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 12 bytes inside of freed 96-byte region [ffff888000684200, ffff888000684260) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x684 flags: 0x7ff00000000000(node=0|zone=0|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 007ff00000000000 ffff888015442280 ffffea0000491a00 dead000000000002 raw: 0000000000000000 0000000000200020 00000001ffffefff 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 62, tgid 62 (kworker/u32:3), ts 63679124260, free_ts 61951603632 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468 prep_new_page mm/page_alloc.c:1476 [inline] get_page_from_freelist+0x136a/0x2df0 mm/page_alloc.c:3402 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4660 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x56/0x110 mm/slub.c:2264 allocate_slab mm/slub.c:2427 [inline] new_slab+0x84/0x260 mm/slub.c:2480 ___slab_alloc+0xdac/0x1870 mm/slub.c:3666 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3756 __slab_alloc_node mm/slub.c:3809 [inline] slab_alloc_node mm/slub.c:3988 [inline] kmalloc_trace_noprof+0x2c5/0x310 mm/slub.c:4147 kmalloc_noprof include/linux/slab.h:660 [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 mld_sendpack+0x5a9/0x11d0 net/ipv6/mcast.c:1807 mld_send_initial_cr.part.0+0x1a1/0x260 net/ipv6/mcast.c:2236 mld_send_initial_cr include/linux/refcount.h:192 [inline] ipv6_mc_dad_complete+0x22c/0x2b0 net/ipv6/mcast.c:2244 addrconf_dad_completed+0xd42/0x1060 net/ipv6/addrconf.c:4339 addrconf_dad_work+0x807/0x1500 net/ipv6/addrconf.c:4267 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231 page last free pid 111 tgid 111 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_folios+0x991/0x1310 mm/page_alloc.c:2614 shrink_folio_list+0x348a/0x4150 mm/vmscan.c:1446 evict_folios+0x6e6/0x1bf0 mm/vmscan.c:4553 try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4749 shrink_one+0x3f8/0x7c0 mm/vmscan.c:4788 shrink_many mm/vmscan.c:4851 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951 shrink_node mm/vmscan.c:5910 [inline] kswapd_shrink_node mm/vmscan.c:6720 [inline] balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180 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 Memory state around the buggy address: ffff888000684100: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888000684180: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888000684200: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888000684280: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff888000684300: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ==================================================================