================================================================== BUG: KASAN: slab-use-after-free in rht_shrink_below_30 include/linux/rhashtable.h:199 [inline] BUG: KASAN: slab-use-after-free in __rhashtable_remove_fast_one include/linux/rhashtable.h:1123 [inline] BUG: KASAN: slab-use-after-free in __rhashtable_remove_fast include/linux/rhashtable.h:1149 [inline] BUG: KASAN: slab-use-after-free in rhashtable_remove_fast include/linux/rhashtable.h:1178 [inline] BUG: KASAN: slab-use-after-free in xfs_buf_rele_cached fs/xfs/xfs_buf.c:923 [inline] BUG: KASAN: slab-use-after-free in xfs_buf_rele+0xf51/0xf80 fs/xfs/xfs_buf.c:948 Read of size 4 at addr ffff88803cca6400 by task syz.3.72/6358 CPU: 0 UID: 0 PID: 6358 Comm: syz.3.72 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 rht_shrink_below_30 include/linux/rhashtable.h:199 [inline] __rhashtable_remove_fast_one include/linux/rhashtable.h:1123 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1149 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1178 [inline] xfs_buf_rele_cached fs/xfs/xfs_buf.c:923 [inline] xfs_buf_rele+0xf51/0xf80 fs/xfs/xfs_buf.c:948 xfs_buftarg_shrink_scan+0x24a/0x2e0 fs/xfs/xfs_buf.c:1650 do_shrink_slab+0x6df/0x10d0 mm/shrinker.c:437 shrink_slab+0xdf2/0x1150 mm/shrinker.c:664 drop_slab_node mm/vmscan.c:434 [inline] drop_slab+0x14a/0x290 mm/vmscan.c:452 drop_caches_sysctl_handler+0xc7/0x170 fs/drop_caches.c:68 proc_sys_call_handler+0x4c9/0x830 fs/proc/proc_sysctl.c:600 do_iter_readv_writev+0x62b/0x8d0 fs/read_write.c:-1 vfs_writev+0x345/0x9a0 fs/read_write.c:1059 do_writev+0x15a/0x2e0 fs/read_write.c:1105 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faa3b49bf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007faa396f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007faa3b715fa0 RCX: 00007faa3b49bf79 RDX: 0000000000000001 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007faa3b5327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faa3b716038 R14: 00007faa3b715fa0 R15: 00007fffe5624548 Allocated by task 6379: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5177 [inline] __kvmalloc_node_noprof+0x3c2/0x8e0 mm/slub.c:6668 bucket_table_alloc lib/rhashtable.c:186 [inline] rhashtable_init_noprof+0x536/0xa80 lib/rhashtable.c:1076 xfs_perag_alloc fs/xfs/libxfs/xfs_ag.c:238 [inline] xfs_initialize_perag+0x284/0x630 fs/xfs/libxfs/xfs_ag.c:279 xfs_mountfs+0xaf2/0x22e0 fs/xfs/xfs_mount.c:997 xfs_fs_fill_super+0x11b5/0x1600 fs/xfs/xfs_super.c:1947 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5797: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2670 [inline] slab_free mm/slub.c:6082 [inline] kfree+0x1c1/0x690 mm/slub.c:6399 rhashtable_free_and_destroy+0x7e8/0x940 lib/rhashtable.c:1174 xfs_group_free+0x166/0x370 fs/xfs/libxfs/xfs_group.c:171 xfs_free_perag_range+0x36/0x60 fs/xfs/libxfs/xfs_ag.c:133 xfs_unmountfs+0x2db/0x320 fs/xfs/xfs_mount.c:1362 xfs_fs_put_super+0x65/0x160 fs/xfs/xfs_super.c:1234 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2294 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803cca6400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of freed 512-byte region [ffff88803cca6400, ffff88803cca6600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3cca4 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe0dc80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe0dc80 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000002 ffffea0000f32901 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5168, tgid 5168 (udevadm), ts 27003932976, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3950 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5245 alloc_slab_page mm/slub.c:3238 [inline] allocate_slab+0x77/0x660 mm/slub.c:3411 new_slab mm/slub.c:3469 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7091 refill_sheaf mm/slub.c:2787 [inline] __pcs_replace_empty_main+0x328/0x5f0 mm/slub.c:4536 alloc_from_pcs mm/slub.c:4639 [inline] slab_alloc_node mm/slub.c:4773 [inline] __kmalloc_cache_noprof+0x44e/0x690 mm/slub.c:5292 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] kernfs_fop_open+0x39a/0xcb0 fs/kernfs/file.c:641 do_dentry_open+0x83d/0x13e0 fs/open.c:949 vfs_open+0x3b/0x350 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e3d/0x38a0 fs/namei.c:4830 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page_owner free stack trace missing Memory state around the buggy address: ffff88803cca6300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803cca6380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88803cca6400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803cca6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803cca6500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================