================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0xa46/0xb30 fs/jfs/jfs_txnmgr.c:2737 Read of size 4 at addr ffff88803144ca94 by task jfsCommit/111 CPU: 1 UID: 0 PID: 111 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 jfs_lazycommit+0xa46/0xb30 fs/jfs/jfs_txnmgr.c:2737 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 26037: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] jfs_fill_super+0xca/0x1040 fs/jfs/super.c:452 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1691 vfs_get_tree+0x8e/0x340 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount fs/namespace.c:3727 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4037 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount fs/namespace.c:4215 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 24990: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2530 [inline] slab_free mm/slub.c:6619 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6826 generic_shutdown_super+0x156/0x390 fs/super.c:642 kill_block_super+0x3b/0x90 fs/super.c:1722 deactivate_locked_super+0xc1/0x1a0 fs/super.c:473 deactivate_super fs/super.c:506 [inline] deactivate_super+0xde/0x100 fs/super.c:502 cleanup_mnt+0x225/0x450 fs/namespace.c:1327 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x130 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+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803144ca00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff88803144ca00, ffff88803144cb00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3144c head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ff26b40 ffffea0001a64d00 dead000000000004 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ff26b40 ffffea0001a64d00 dead000000000004 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0000c51301 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 5836, tgid 5836 (syz-executor), ts 118541345556, free_ts 118462623588 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3046 [inline] allocate_slab mm/slub.c:3219 [inline] new_slab+0x24a/0x360 mm/slub.c:3273 ___slab_alloc+0xdc4/0x1ae0 mm/slub.c:4643 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4762 __slab_alloc_node mm/slub.c:4838 [inline] slab_alloc_node mm/slub.c:5260 [inline] __kmalloc_cache_noprof+0x477/0x780 mm/slub.c:5750 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ____ip_mc_inc_group+0x403/0x10f0 net/ipv4/igmp.c:1535 __ip_mc_inc_group net/ipv4/igmp.c:1573 [inline] ip_mc_inc_group net/ipv4/igmp.c:1579 [inline] ip_mc_up+0x154/0x3b0 net/ipv4/igmp.c:1880 inetdev_event+0xafb/0x18a0 net/ipv4/devinet.c:1630 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9676 netif_change_flags+0x108/0x160 net/core/dev.c:9705 do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3151 page last free pid 49 tgid 49 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4962 [inline] slab_alloc_node mm/slub.c:5272 [inline] __kmalloc_cache_noprof+0x274/0x780 mm/slub.c:5750 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] nsim_fib6_rt_create drivers/net/netdevsim/fib.c:547 [inline] nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:752 [inline] nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline] nsim_fib_event drivers/net/netdevsim/fib.c:889 [inline] nsim_fib_event_work+0x1938/0x6da0 drivers/net/netdevsim/fib.c:1493 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88803144c980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803144ca00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803144ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803144cb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803144cb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================