syzbot

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BUG: KASAN: use-after-free in process_notifier+0x343/0x7b0 drivers/misc/uid_sys_stats.c:707
Write of size 8 at addr ffff8881137ff9d8 by task syz-executor.5/914

CPU: 0 PID: 914 Comm: syz-executor.5 Not tainted 6.1.25-syzkaller-00063-g4b3ab91671d8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __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: 0033:0x7f14a24a88d9
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:00007f14a317b240 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: 0000000000000000 RBX: 00007f14a2450fc0 RCX: 00007f14a24a88d9
RDX: 00007f14a2450fc0 RSI: 0000000000000058 RDI: 00007ffc3a872e10
RBP: 00007f14a317b6c0 R08: 00007f14a317b6c0 R09: 00007ffc3a872ef7
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffb0
R13: 000000000000000b R14: 00007ffc3a872e10 R15: 00007ffc3a872ef8
 </TASK>

Allocated by task 914:
 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 10463:
 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 ffff8881137ff980
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 88 bytes inside of
 96-byte region [ffff8881137ff980, ffff8881137ff9e0)

The buggy address belongs to the physical page:
page:ffffea00044dffc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1137ff
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea000482a400 dead000000000003 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 397, tgid 397 (syz-executor.4), ts 110546582008, free_ts 110531538614
 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_list+0xf6/0x6c0 mm/page_alloc.c:3628
 release_pages+0xf7f/0xfe0 mm/swap.c:1055
 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:314
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu mm/mmu_gather.c:261 [inline]
 tlb_finish_mmu+0x1e0/0x3f0 mm/mmu_gather.c:361
 exit_mmap+0x3e5/0x8a0 mm/mmap.c:3329
 __mmput+0x95/0x310 kernel/fork.c:1272
 mmput+0x56/0x170 kernel/fork.c:1295
 exit_mm kernel/exit.c:566 [inline]
 do_exit+0xb29/0x2b80 kernel/exit.c:862
 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

Memory state around the buggy address:
 ffff8881137ff880: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff8881137ff900: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8881137ff980: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                                    ^
 ffff8881137ffa00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8881137ffa80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
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