================================================================== BUG: KASAN: use-after-free in process_notifier+0x343/0x7b0 drivers/misc/uid_sys_stats.c:707 Write of size 8 at addr ffff88812c340058 by task syz-executor.3/11749 CPU: 0 PID: 11749 Comm: syz-executor.3 Not tainted 6.1.25-syzkaller-00070-gc0e84be92384 #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 __do_sys_exit_group kernel/exit.c:1036 [inline] __se_sys_exit_group kernel/exit.c:1034 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1034 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 RIP: 0033:0x7f4a31a7cae9 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:00007f4a32748af8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f4a31a7cae9 RDX: 00007f4a31ad3b2b RSI: 0000000000000000 RDI: 000000000000000b RBP: 00007f4a31ac847a R08: 00007ffddfda50b0 R09: 000000000000000b R10: 00007ffddfda5080 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f4a31b9c2c0 R15: 00007ffddfd21dc8 Allocated by task 11749: 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 __do_sys_exit_group kernel/exit.c:1036 [inline] __se_sys_exit_group kernel/exit.c:1034 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1034 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 Freed by task 916: 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 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 ffff88812c340000 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 88 bytes inside of 96-byte region [ffff88812c340000, ffff88812c340060) The buggy address belongs to the physical page: page:ffffea0004b0d000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88812c340700 pfn:0x12c340 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea00045379c0 dead000000000005 ffff888100042900 raw: ffff88812c340700 000000008020001f 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 383, tgid 383 (syz-executor.0), ts 106267249279, free_ts 106255067241 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+0xa42/0x1ce0 fs/ext4/inode.c:651 ext4_getblk+0x1eb/0x7b0 fs/ext4/inode.c:864 ext4_bread+0x2f/0x180 fs/ext4/inode.c:920 ext4_append+0x31f/0x5b0 fs/ext4/namei.c:83 ext4_init_new_dir+0x33f/0x620 fs/ext4/namei.c:2955 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_slab+0xce/0x1a0 mm/slub.c:2036 free_slab mm/slub.c:2051 [inline] discard_slab+0x29/0x40 mm/slub.c:2057 __slab_free+0x205/0x280 mm/slub.c:3594 do_slab_free mm/slub.c:3635 [inline] ___cache_free+0xc6/0xd0 mm/slub.c:3688 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:168 qlist_free_all+0x52/0xc0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x15a/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:310 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768 slab_alloc_node mm/slub.c:3418 [inline] slab_alloc mm/slub.c:3426 [inline] __kmem_cache_alloc_lru mm/slub.c:3433 [inline] kmem_cache_alloc+0x175/0x2c0 mm/slub.c:3442 getname_flags+0xba/0x520 fs/namei.c:139 getname fs/namei.c:218 [inline] __do_sys_unlink fs/namei.c:4368 [inline] __se_sys_unlink fs/namei.c:4366 [inline] __x64_sys_unlink+0x3c/0x50 fs/namei.c:4366 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88812c33ff00: fc fc fc fc 00 00 00 00 00 00 00 fc fc fc fc 00 ffff88812c33ff80: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc >ffff88812c340000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88812c340080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88812c340100: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================