syzbot

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BUG: KASAN: use-after-free in cleancache_fs_enabled_mapping include/linux/cleancache.h:56 [inline]
BUG: KASAN: use-after-free in cleancache_invalidate_page include/linux/cleancache.h:110 [inline]
BUG: KASAN: use-after-free in unaccount_page_cache_page+0x9e0/0xac0 mm/filemap.c:175
Read of size 4 at addr ffff8881164fc470 by task syz.6.4435/15993

CPU: 1 PID: 15993 Comm: syz.6.4435 Tainted: G        W         5.10.238-syzkaller-00008-g59e9a7228857 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 cleancache_fs_enabled_mapping include/linux/cleancache.h:56 [inline]
 cleancache_invalidate_page include/linux/cleancache.h:110 [inline]
 unaccount_page_cache_page+0x9e0/0xac0 mm/filemap.c:175
 __delete_from_page_cache+0xc4/0x460 mm/filemap.c:243
 __remove_mapping+0x562/0x690 mm/vmscan.c:985
 shrink_page_list+0x2109/0x4120 mm/vmscan.c:1498
 shrink_inactive_list+0x4f4/0xe80 mm/vmscan.c:2075
 shrink_list mm/vmscan.c:2294 [inline]
 shrink_lruvec+0x2246/0x2770 mm/vmscan.c:5473
 shrink_node_memcgs mm/vmscan.c:5660 [inline]
 shrink_node+0xf0c/0x2690 mm/vmscan.c:5690
 shrink_zones mm/vmscan.c:5896 [inline]
 do_try_to_free_pages+0x5db/0x1560 mm/vmscan.c:5954
 try_to_free_mem_cgroup_pages+0x233/0x5b0 mm/vmscan.c:6272
 try_charge+0x42b/0x14e0 mm/memcontrol.c:2745
 __mem_cgroup_charge+0x14c/0x6d0 mm/memcontrol.c:6871
 mem_cgroup_charge include/linux/memcontrol.h:458 [inline]
 shmem_add_to_page_cache+0x55e/0xe10 mm/shmem.c:703
 shmem_getpage_gfp+0x8e8/0x2110 mm/shmem.c:1956
 shmem_getpage mm/shmem.c:165 [inline]
 shmem_write_begin+0xce/0x1b0 mm/shmem.c:2501
 generic_perform_write+0x2be/0x510 mm/filemap.c:3509
 __generic_file_write_iter+0x24b/0x480 mm/filemap.c:3638
 generic_file_write_iter+0xa9/0x1d0 mm/filemap.c:3670
 __kernel_write+0x55a/0x910 fs/read_write.c:550
 dump_emit+0x240/0x360 fs/coredump.c:855
 dump_user_range+0x6a/0x1a0 fs/coredump.c:908
 elf_core_dump+0x278a/0x2bc0 fs/binfmt_elf.c:2290
 do_coredump+0x1ac9/0x27f0 fs/coredump.c:817
 get_signal+0xf23/0x12e0 kernel/signal.c:2779
 arch_do_signal_or_restart+0xbf/0x10f0 arch/x86/kernel/signal.c:805
 handle_signal_work kernel/entry/common.c:145 [inline]
 exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 irqentry_exit_to_user_mode+0x4e/0x80 kernel/entry/common.c:287
 irqentry_exit+0x12/0x60 kernel/entry/common.c:375
 exc_general_protection+0x1ca/0x250 arch/x86/kernel/traps.c:557
 asm_exc_general_protection+0x1e/0x30 arch/x86/include/asm/idtentry.h:565
RIP: 0033:0x7f33541ba931
Code: 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:0000200000000080 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f33543e2160 RCX: 00007f33541ba929
RDX: 00002000000000c0 RSI: 0000200000000080 RDI: 00000000020a0000
RBP: 00007f335423cb39 R08: 0000200000000140 R09: 0000200000000140
R10: 0000200000000100 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f33543e2160 R15: 00007ffd8e5d6338

Allocated by task 14803:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960
 shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3820
 alloc_inode fs/inode.c:233 [inline]
 new_inode_pseudo+0x62/0x210 fs/inode.c:968
 new_inode+0x28/0x1e0 fs/inode.c:997
 shmem_get_inode+0x34a/0x9d0 mm/shmem.c:2315
 shmem_symlink+0x9e/0x500 mm/shmem.c:3122
 vfs_symlink+0x380/0x520 fs/namei.c:4099
 do_symlinkat+0x103/0x3b0 fs/namei.c:4126
 __do_sys_symlinkat fs/namei.c:4140 [inline]
 __se_sys_symlinkat fs/namei.c:4137 [inline]
 __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4137
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x105/0x1040 kernel/rcu/tree.c:3050
 destroy_inode fs/inode.c:288 [inline]
 evict+0x857/0x910 fs/inode.c:629
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 do_unlinkat+0x33f/0x670 fs/namei.c:4042
 __do_sys_unlink fs/namei.c:4082 [inline]
 __se_sys_unlink fs/namei.c:4080 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4080
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Second to last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x105/0x1040 kernel/rcu/tree.c:3050
 destroy_inode fs/inode.c:288 [inline]
 evict+0x857/0x910 fs/inode.c:629
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 d_delete_notify include/linux/fsnotify.h:267 [inline]
 vfs_rmdir+0x2bd/0x3e0 fs/namei.c:3865
 do_rmdir+0x218/0x620 fs/namei.c:3912
 __do_sys_unlinkat fs/namei.c:4076 [inline]
 __se_sys_unlinkat fs/namei.c:4070 [inline]
 __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4070
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff8881164fc3a0
 which belongs to the cache shmem_inode_cache of size 800
The buggy address is located 208 bytes inside of
 800-byte region [ffff8881164fc3a0, ffff8881164fc6c0)
The buggy address belongs to the page:
page:ffffea0004593f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881164fef20 pfn:0x1164fc
head:ffffea0004593f00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 ffffea0004664c08 ffffea00049cc408 ffff88810018b800
raw: ffff8881164fef20 0000000000110002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 8686, ts 314575621953, free_ts 314493279305
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5357
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960
 shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3820
 alloc_inode fs/inode.c:233 [inline]
 new_inode_pseudo+0x62/0x210 fs/inode.c:968
 new_inode+0x28/0x1e0 fs/inode.c:997
 shmem_get_inode+0x34a/0x9d0 mm/shmem.c:2315
 shmem_symlink+0x9e/0x500 mm/shmem.c:3122
 vfs_symlink+0x380/0x520 fs/namei.c:4099
 do_symlinkat+0x103/0x3b0 fs/namei.c:4126
 __do_sys_symlinkat fs/namei.c:4140 [inline]
 __se_sys_symlinkat fs/namei.c:4137 [inline]
 __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4137
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 __free_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629
 free_the_page mm/page_alloc.c:5418 [inline]
 __free_pages+0xdd/0x380 mm/page_alloc.c:5427
 __free_slab+0xcf/0x190 mm/slub.c:1894
 free_slab mm/slub.c:1909 [inline]
 discard_slab mm/slub.c:1915 [inline]
 unfreeze_partials+0x15f/0x190 mm/slub.c:2410
 put_cpu_partial+0xc1/0x180 mm/slub.c:2446
 __slab_free+0x2c9/0x3a0 mm/slub.c:3095
 do_slab_free mm/slub.c:3191 [inline]
 ___cache_free+0x111/0x130 mm/slub.c:3210
 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc_trace+0x160/0x2e0 mm/slub.c:2972
 kmalloc include/linux/slab.h:552 [inline]
 p9_client_getattr_dotl+0x5a/0x360 net/9p/client.c:1764
 v9fs_inode_from_fid_dotl+0x2c/0x220 fs/9p/vfs_inode_dotl.c:152
 v9fs_vfs_lookup+0x2fe/0x3c0 fs/9p/vfs_inode.c:-1

Memory state around the buggy address:
 ffff8881164fc300: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881164fc380: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881164fc400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8881164fc480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881164fc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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