================================================================== BUG: KASAN: use-after-free in process_notifier+0x343/0x7b0 drivers/misc/uid_sys_stats.c:707 Write of size 8 at addr ffff88812b102c58 by task syz-executor.0/20523 CPU: 0 PID: 20523 Comm: syz-executor.0 Not tainted 6.1.25-syzkaller-00083-g5b0878fc616a #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 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2eb667cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2eb73b3178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f2eb679c2c8 RCX: 00007f2eb667cae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2eb679c2c8 RBP: 00007f2eb679c2c0 R08: 00007f2eb73b36c0 R09: 00007f2eb73b36c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2eb679c2cc R13: 000000000000006e R14: 00007ffd734f90b0 R15: 00007ffd734f9198 Allocated by task 20523: 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 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 6: 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 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 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 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_device_event+0xa0/0xd0 net/netfilter/nf_nat_masquerade.c:162 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 rtnl_newlink_create net/core/rtnetlink.c:3395 [inline] __rtnl_newlink net/core/rtnetlink.c:3581 [inline] rtnl_newlink+0x1c67/0x1f80 net/core/rtnetlink.c:3594 rtnetlink_rcv_msg+0x9a5/0xca0 net/core/rtnetlink.c:6091 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2553 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6109 netlink_unicast_kernel net/netlink/af_netlink.c:1328 [inline] netlink_unicast+0x8ee/0xad0 net/netlink/af_netlink.c:1354 netlink_sendmsg+0xa15/0xd30 net/netlink/af_netlink.c:1931 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x5dc/0x9d0 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2572 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 The buggy address belongs to the object at ffff88812b102c00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 88 bytes inside of 96-byte region [ffff88812b102c00, ffff88812b102c60) The buggy address belongs to the physical page: page:ffffea0004ac4080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12b102 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 dead000000000100 dead000000000122 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 384, tgid 384 (syz-executor.2), ts 314153104250, free_ts 314147281192 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_node+0xa3/0x1e0 mm/slab_common.c:964 kmalloc_node include/linux/slab.h:579 [inline] kvmalloc_node+0x72/0x190 mm/util.c:586 kvmalloc include/linux/slab.h:706 [inline] alloc_fdtable+0x163/0x2a0 fs/file.c:141 dup_fd+0x617/0x980 fs/file.c:354 copy_files+0xe6/0x200 kernel/fork.c:1711 copy_process+0x11df/0x3490 kernel/fork.c:2332 kernel_clone+0x229/0x890 kernel/fork.c:2764 __do_sys_clone kernel/fork.c:2907 [inline] __se_sys_clone kernel/fork.c:2891 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2891 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 _pgd_free arch/x86/mm/pgtable.c:420 [inline] pgd_free+0x17d/0x190 arch/x86/mm/pgtable.c:476 mm_free_pgd kernel/fork.c:814 [inline] __mmdrop+0xb0/0x3e0 kernel/fork.c:865 mmdrop include/linux/sched/mm.h:50 [inline] __mmput+0x304/0x310 kernel/fork.c:1283 mmput+0x56/0x170 kernel/fork.c:1295 exit_mm kernel/exit.c:566 [inline] do_exit+0xb29/0x2b80 kernel/exit.c:862 __do_sys_exit kernel/exit.c:992 [inline] __se_sys_exit kernel/exit.c:990 [inline] __ia32_sys_exit+0x0/0x40 kernel/exit.c:990 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: ffff88812b102b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88812b102b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc >ffff88812b102c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88812b102c80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88812b102d00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================