================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: slab-use-after-free in mapping_unevictable include/linux/pagemap.h:269 [inline] BUG: KASAN: slab-use-after-free in folio_evictable+0x7b/0x270 mm/internal.h:435 Read of size 8 at addr ffff8880226d6d48 by task kswapd0/112 CPU: 3 UID: 0 PID: 112 Comm: kswapd0 Not tainted 6.12.0-syzkaller-09435-g2c22dc1ee3a1 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] mapping_unevictable include/linux/pagemap.h:269 [inline] folio_evictable+0x7b/0x270 mm/internal.h:435 sort_folio mm/vmscan.c:4299 [inline] scan_folios mm/vmscan.c:4424 [inline] isolate_folios+0x546/0x3830 mm/vmscan.c:4550 evict_folios+0x187/0x19c0 mm/vmscan.c:4581 try_to_shrink_lruvec+0x61e/0xa80 mm/vmscan.c:4789 shrink_one+0x3e3/0x7b0 mm/vmscan.c:4834 shrink_many mm/vmscan.c:4897 [inline] lru_gen_shrink_node mm/vmscan.c:4975 [inline] shrink_node+0xbf0/0x3f20 mm/vmscan.c:5956 kswapd_shrink_node mm/vmscan.c:6785 [inline] balance_pgdat+0xc1f/0x18f0 mm/vmscan.c:6977 kswapd+0x5f8/0xc30 mm/vmscan.c:7246 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 37: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4104 [inline] slab_alloc_node mm/slub.c:4153 [inline] kmem_cache_alloc_lru_noprof+0x1c8/0x3b0 mm/slub.c:4172 shmem_alloc_inode+0x25/0x50 mm/shmem.c:4980 alloc_inode+0x5d/0x230 fs/inode.c:336 new_inode_pseudo fs/inode.c:1174 [inline] new_inode+0x22/0x210 fs/inode.c:1193 __shmem_get_inode mm/shmem.c:2874 [inline] shmem_get_inode+0x194/0xf00 mm/shmem.c:2948 shmem_mknod+0x1a8/0x450 mm/shmem.c:3670 vfs_mknod+0x5d7/0x8e0 fs/namei.c:4189 handle_create drivers/base/devtmpfs.c:219 [inline] handle drivers/base/devtmpfs.c:384 [inline] devtmpfs_work_loop+0x1a8/0x7d0 drivers/base/devtmpfs.c:399 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:441 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 16: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kmem_cache_free+0x152/0x4c0 mm/slub.c:4700 i_callback+0x43/0x70 fs/inode.c:325 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0x79d/0x14d0 kernel/rcu/tree.c:2823 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 run_ksoftirqd kernel/softirq.c:943 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:935 smpboot_thread_fn+0x661/0xa30 kernel/smpboot.c:164 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:544 __call_rcu_common.constprop.0+0x99/0x7a0 kernel/rcu/tree.c:3086 destroy_inode+0x12c/0x1b0 fs/inode.c:391 evict+0x5ed/0x960 fs/inode.c:827 iput_final fs/inode.c:1946 [inline] iput fs/inode.c:1972 [inline] iput+0x52a/0x890 fs/inode.c:1958 do_unlinkat+0x5c3/0x760 fs/namei.c:4594 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __ia32_sys_unlink+0xc4/0x110 fs/namei.c:4633 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff8880226d6880 which belongs to the cache shmem_inode_cache of size 1544 The buggy address is located 1224 bytes inside of freed 1544-byte region [ffff8880226d6880, ffff8880226d6e88) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880226d7590 pfn:0x226d0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88801e417701 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff888040489cc0 ffffea00008a7810 ffffea00008dd410 raw: ffff8880226d7590 0000000000130003 00000001f5000000 ffff88801e417701 head: 00fff00000000240 ffff888040489cc0 ffffea00008a7810 ffffea00008dd410 head: ffff8880226d7590 0000000000130003 00000001f5000000 ffff88801e417701 head: 00fff00000000003 ffffea000089b401 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 37, tgid 37 (kdevtmpfs), ts 5548691532, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2408 [inline] allocate_slab mm/slub.c:2574 [inline] new_slab+0x2c9/0x410 mm/slub.c:2627 ___slab_alloc+0xd1d/0x16e0 mm/slub.c:3815 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 __slab_alloc_node mm/slub.c:3980 [inline] slab_alloc_node mm/slub.c:4141 [inline] kmem_cache_alloc_lru_noprof+0xf0/0x3b0 mm/slub.c:4172 shmem_alloc_inode+0x25/0x50 mm/shmem.c:4980 alloc_inode+0x5d/0x230 fs/inode.c:336 new_inode_pseudo fs/inode.c:1174 [inline] new_inode+0x22/0x210 fs/inode.c:1193 __shmem_get_inode mm/shmem.c:2874 [inline] shmem_get_inode+0x194/0xf00 mm/shmem.c:2948 shmem_mknod+0x1a8/0x450 mm/shmem.c:3670 vfs_mknod+0x5d7/0x8e0 fs/namei.c:4189 handle_create drivers/base/devtmpfs.c:219 [inline] handle drivers/base/devtmpfs.c:384 [inline] devtmpfs_work_loop+0x1a8/0x7d0 drivers/base/devtmpfs.c:399 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:441 page_owner free stack trace missing Memory state around the buggy address: ffff8880226d6c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880226d6c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880226d6d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880226d6d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880226d6e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================