================================================================== BUG: KASAN: use-after-free in process_notifier+0x343/0x7b0 drivers/misc/uid_sys_stats.c:707 Write of size 8 at addr ffff888120a42f58 by task syz-executor.2/18913 CPU: 0 PID: 18913 Comm: syz-executor.2 Not tainted 6.1.25-syzkaller-00051-g2a13641a142a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356 process_notifier+0x343/0x7b0 drivers/misc/uid_sys_stats.c:707 notifier_call_chain kernel/notifier.c:87 [inline] blocking_notifier_call_chain+0xbb/0x140 kernel/notifier.c:382 profile_task_exit+0x1e/0x30 kernel/profile.c:146 do_exit+0x2c1/0x2b80 kernel/exit.c:819 do_group_exit+0x21a/0x2d0 kernel/exit.c:1025 get_signal+0x169d/0x1820 kernel/signal.c:2866 arch_do_signal_or_restart+0xb0/0x16f0 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop+0x6b/0xa0 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:297 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:299 RIP: 0033:0x7fad166a88d9 Code: ff ff eb d2 e8 f8 62 fd ff 0f 1f 84 00 00 00 00 00 b8 ea ff ff ff 48 85 ff 74 2c 48 85 d2 74 27 49 89 c8 b8 b3 01 00 00 0f 05 <48> 85 c0 7c 18 74 01 c3 31 ed 48 83 e4 f0 4c 89 c7 ff d2 48 89 c7 RSP: 002b:00007fad159bd240 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3 RAX: 0000000000000000 RBX: 00007fad16650fc0 RCX: 00007fad166a88d9 RDX: 00007fad16650fc0 RSI: 0000000000000058 RDI: 00007ffe7b767890 RBP: 00007fad159bd6c0 R08: 00007fad159bd6c0 R09: 00007ffe7b767977 R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffb0 R13: 000000000000006e R14: 00007ffe7b767890 R15: 00007ffe7b767978 Allocated by task 18913: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x9c/0xb0 mm/kasan/common.c:388 kasan_kmalloc include/linux/kasan.h:212 [inline] kmalloc_trace+0x44/0xa0 mm/slab_common.c:1052 kmalloc include/linux/slab.h:553 [inline] process_notifier+0x2c1/0x7b0 drivers/misc/uid_sys_stats.c:695 notifier_call_chain kernel/notifier.c:87 [inline] blocking_notifier_call_chain+0xbb/0x140 kernel/notifier.c:382 profile_task_exit+0x1e/0x30 kernel/profile.c:146 do_exit+0x2c1/0x2b80 kernel/exit.c:819 do_group_exit+0x21a/0x2d0 kernel/exit.c:1025 get_signal+0x169d/0x1820 kernel/signal.c:2866 arch_do_signal_or_restart+0xb0/0x16f0 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop+0x6b/0xa0 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:297 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:299 Freed by task 17669: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1744 [inline] slab_free_freelist_hook mm/slub.c:1770 [inline] slab_free mm/slub.c:3681 [inline] __kmem_cache_free+0x218/0x3b0 mm/slub.c:3694 kfree+0x7a/0xf0 mm/slab_common.c:1009 update_stats_workfn+0x36b/0x3e0 drivers/misc/uid_sys_stats.c:674 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2296 worker_thread+0xa60/0x1260 kernel/workqueue.c:2443 kthread+0x26d/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 insert_work+0x56/0x310 kernel/workqueue.c:1365 __queue_work+0x9d0/0xd80 kernel/workqueue.c:1524 queue_work_on+0x105/0x170 kernel/workqueue.c:1552 queue_work include/linux/workqueue.h:509 [inline] schedule_work include/linux/workqueue.h:570 [inline] nf_nat_masq_schedule+0x4bc/0x600 net/netfilter/nf_nat_masquerade.c:130 masq_inet6_event+0x124/0x180 net/netfilter/nf_nat_masquerade.c:295 notifier_call_chain kernel/notifier.c:87 [inline] atomic_notifier_call_chain+0x95/0x100 kernel/notifier.c:225 inet6addr_notifier_call_chain+0x24/0x30 net/ipv6/addrconf_core.c:109 addrconf_ifdown+0xe5e/0x1ab0 net/ipv6/addrconf.c:3902 addrconf_notify+0x32f/0xe10 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:1952 [inline] call_netdevice_notifiers_extack net/core/dev.c:1990 [inline] call_netdevice_notifiers net/core/dev.c:2004 [inline] dev_close_many+0x37c/0x530 net/core/dev.c:1552 unregister_netdevice_many+0x49f/0x17f0 net/core/dev.c:10823 unregister_netdevice_queue+0x2e6/0x350 net/core/dev.c:10780 unregister_netdevice include/linux/netdevice.h:3096 [inline] __tun_detach+0xcf9/0x14c0 drivers/net/tun.c:684 tun_detach drivers/net/tun.c:700 [inline] tun_chr_close+0x92/0x140 drivers/net/tun.c:3469 __fput+0x3ab/0x870 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x24d/0x2e0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x8b/0xa0 kernel/entry/common.c:171 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 kvfree_call_rcu+0x9f/0x800 kernel/rcu/tree.c:3343 kernfs_unlink_open_file+0x327/0x3d0 fs/kernfs/file.c:629 kernfs_fop_release+0x253/0x310 fs/kernfs/file.c:801 __fput+0x3ab/0x870 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x24d/0x2e0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x8b/0xa0 kernel/entry/common.c:171 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888120a42f00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 88 bytes inside of 96-byte region [ffff888120a42f00, ffff888120a42f60) The buggy address belongs to the physical page: page:ffffea0004829080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x120a42 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea000445c480 dead000000000005 ffff888100042900 raw: 0000000000000000 0000000080200020 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 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 294, tgid 294 (syz-executor), ts 30286665847, free_ts 30285932427 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2582 prep_new_page+0x1b/0x110 mm/page_alloc.c:2589 get_page_from_freelist+0x2762/0x27f0 mm/page_alloc.c:4387 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5664 allocate_slab mm/slub.c:1959 [inline] new_slab+0xce/0x4c0 mm/slub.c:2012 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3200 __slab_alloc+0x5d/0xa0 mm/slub.c:3299 slab_alloc_node mm/slub.c:3384 [inline] __kmem_cache_alloc_node+0x1af/0x250 mm/slub.c:3457 __do_kmalloc_node mm/slab_common.c:956 [inline] __kmalloc+0xa3/0x1e0 mm/slab_common.c:970 kmalloc_array include/linux/slab.h:605 [inline] kcalloc include/linux/slab.h:636 [inline] ext4_find_extent+0x370/0xdb0 fs/ext4/extents.c:914 ext4_ext_map_blocks+0x255/0x71e0 fs/ext4/extents.c:4103 ext4_map_blocks+0x40f/0x1ce0 fs/ext4/inode.c:576 ext4_append+0x243/0x5b0 fs/ext4/namei.c:75 ext4_init_new_dir+0x33f/0x620 fs/ext4/namei.c:2955 ext4_mkdir+0x4f2/0xce0 fs/ext4/namei.c:3001 vfs_mkdir+0x398/0x570 fs/namei.c:4036 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1494 [inline] free_pcp_prepare mm/page_alloc.c:1568 [inline] free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3486 free_unref_page+0x8d/0x480 mm/page_alloc.c:3582 free_the_page mm/page_alloc.c:794 [inline] __free_pages+0x61/0xf0 mm/page_alloc.c:5753 free_pages+0x7c/0x90 mm/page_alloc.c:5764 selinux_genfs_get_sid+0x24d/0x2a0 security/selinux/hooks.c:1303 inode_doinit_with_dentry+0x8d2/0x1070 security/selinux/hooks.c:1498 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6329 security_d_instantiate+0x9f/0x100 security/security.c:2064 d_splice_alias+0x6d/0x390 fs/dcache.c:3146 proc_sys_lookup+0x45b/0x720 fs/proc/proc_sysctl.c:548 lookup_open fs/namei.c:3391 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x10fd/0x2d60 fs/namei.c:3711 do_filp_open+0x230/0x480 fs/namei.c:3741 do_sys_openat2+0x13f/0x850 fs/open.c:1333 do_sys_open fs/open.c:1349 [inline] __do_sys_openat fs/open.c:1365 [inline] __se_sys_openat fs/open.c:1360 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1360 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888120a42e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888120a42e80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888120a42f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888120a42f80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888120a43000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================