================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x77a/0xaa0 fs/jfs/jfs_txnmgr.c:2736 Read of size 4 at addr ffff888044098694 by task jfsCommit/113 CPU: 1 PID: 113 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 jfs_lazycommit+0x77a/0xaa0 fs/jfs/jfs_txnmgr.c:2736 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 10418: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] jfs_fill_super+0xdc/0xab0 fs/jfs/super.c:495 mount_bdev+0x21c/0x2c0 fs/super.c:1651 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1772 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 5775: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 generic_shutdown_super+0x134/0x2b0 fs/super.c:693 kill_block_super+0x44/0x90 fs/super.c:1668 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x3d7/0x460 fs/namespace.c:1259 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:180 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452 drop_sysctl_table+0x394/0x540 fs/proc/proc_sysctl.c:1515 drop_sysctl_table+0x3ab/0x540 fs/proc/proc_sysctl.c:1518 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1536 mpls_dev_sysctl_unregister+0x8b/0xc0 net/mpls/af_mpls.c:1433 mpls_dev_notify+0x533/0x7a0 net/mpls/af_mpls.c:1645 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] unregister_netdevice_many_notify+0x1037/0x1910 net/core/dev.c:11162 unregister_netdevice_many net/core/dev.c:11218 [inline] default_device_exit_batch+0x962/0xa00 net/core/dev.c:11784 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x785/0xb00 net/core/net_namespace.c:656 process_one_work kernel/workqueue.c:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff888044098600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888044098600, ffff888044098700) The buggy address belongs to the physical page: page:ffffea0001102600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x44098 head:ffffea0001102600 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c41b40 ffffea0000ac3a80 dead000000000004 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 7364, tgid 7362 (syz.3.363), ts 353587965762, free_ts 332672698384 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 alloc_slab_page+0x5d/0x180 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa7/0x240 mm/slab_common.c:1020 kmalloc_array include/linux/slab.h:637 [inline] kcalloc include/linux/slab.h:668 [inline] iter_file_splice_write+0x1a4/0xcf0 fs/splice.c:676 do_splice_from fs/splice.c:933 [inline] direct_splice_actor+0xe8/0x130 fs/splice.c:1142 splice_direct_to_actor+0x30b/0x8e0 fs/splice.c:1088 do_splice_direct+0x1d5/0x2f0 fs/splice.c:1194 do_sendfile+0x52b/0xe80 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64+0x145/0x1a0 fs/read_write.c:1308 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x17e/0x2c0 mm/slub.c:3519 mt_alloc_one lib/maple_tree.c:162 [inline] mas_alloc_nodes+0x2f8/0x8c0 lib/maple_tree.c:1267 mas_node_count_gfp lib/maple_tree.c:1347 [inline] mas_preallocate+0xa1f/0x1170 lib/maple_tree.c:5535 vma_iter_prealloc mm/internal.h:1153 [inline] vma_expand+0x668/0x920 mm/mmap.c:658 __mmap_region mm/mmap.c:2756 [inline] mmap_region+0xc94/0x2090 mm/mmap.c:2941 do_mmap+0x98f/0x10a0 mm/mmap.c:1385 vm_mmap_pgoff+0x1c4/0x3f0 mm/util.c:556 Memory state around the buggy address: ffff888044098580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888044098600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888044098680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888044098700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888044098780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================