================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x6d9/0xa10 fs/jfs/jfs_txnmgr.c:2736 Read of size 4 at addr ffff888030553894 by task jfsCommit/121 CPU: 1 UID: 0 PID: 121 Comm: jfsCommit Tainted: G W 6.17.0-rc1-syzkaller-00038-g0cc53520e68b #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 jfs_lazycommit+0x6d9/0xa10 fs/jfs/jfs_txnmgr.c:2736 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6847: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x1a8/0x320 mm/slub.c:4396 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] jfs_fill_super+0xc2/0xd80 fs/jfs/super.c:452 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805 do_mount fs/namespace.c:4133 [inline] __do_sys_mount fs/namespace.c:4344 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4321 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6252: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x195/0x550 mm/slub.c:4879 generic_shutdown_super+0x132/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1766 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1378 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888030553800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888030553800, ffff888030553900) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30552 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff888019841b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff888019841b40 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000001 ffffea0000c15481 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5847, tgid 5847 (syz-executor), ts 104968236680, free_ts 104860244425 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0x8d1/0xdd0 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_noprof+0x145/0x430 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] fib_create_info+0x1728/0x3210 net/ipv4/fib_semantics.c:1402 fib_table_insert+0xc6/0x1b50 net/ipv4/fib_trie.c:1212 fib_magic+0x2c4/0x390 net/ipv4/fib_frontend.c:1133 fib_add_ifaddr+0x144/0x5f0 net/ipv4/fib_frontend.c:1155 fib_inetaddr_event+0x12e/0x190 net/ipv4/fib_frontend.c:1469 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 __inet_insert_ifa+0xa13/0xbf0 net/ipv4/devinet.c:567 inet_rtm_newaddr+0xf3a/0x18b0 net/ipv4/devinet.c:1002 page last free pid 20 tgid 20 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xb59/0xce0 mm/page_alloc.c:2895 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core kernel/rcu/tree.c:2861 [inline] rcu_cpu_kthread+0xbf3/0x1b50 kernel/rcu/tree.c:2949 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888030553780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888030553800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888030553880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888030553900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888030553980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================