================================================================== BUG: KASAN: slab-use-after-free in lbmIODone+0x130e/0x16b0 fs/jfs/jfs_logmgr.c:2192 Read of size 4 at addr ffff88802952c008 by task rcuc/1/28 CPU: 1 UID: 0 PID: 28 Comm: rcuc/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 lbmIODone+0x130e/0x16b0 fs/jfs/jfs_logmgr.c:2192 blk_update_request+0x57b/0xe50 block/blk-mq.c:1016 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1147 blk_complete_reqs block/blk-mq.c:1222 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1227 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] __local_bh_enable_ip+0x16f/0x2b0 kernel/softirq.c:325 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_cpu_kthread+0x11f5/0x1740 kernel/rcu/tree.c:3008 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6251: 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] __kmalloc_cache_noprof+0x3d5/0x680 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] lbmLogInit fs/jfs/jfs_logmgr.c:1819 [inline] lmLogInit+0x3e5/0x1a20 fs/jfs/jfs_logmgr.c:1267 open_inline_log fs/jfs/jfs_logmgr.c:1173 [inline] lmLogOpen+0x4e3/0xf90 fs/jfs/jfs_logmgr.c:1067 jfs_mount_rw+0xf3/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x769/0xda0 fs/jfs/super.c:533 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1887 vfs_get_tree+0x92/0x2a0 fs/super.c:1947 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3772 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3848 do_mount fs/namespace.c:4181 [inline] __do_sys_mount fs/namespace.c:4397 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4374 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5594: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 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:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x1c5/0x6d0 mm/slub.c:6792 lbmLogShutdown fs/jfs/jfs_logmgr.c:1862 [inline] lmLogShutdown+0x456/0x850 fs/jfs/jfs_logmgr.c:1681 lmLogClose+0x28c/0x530 fs/jfs/jfs_logmgr.c:1457 jfs_umount+0x2da/0x3b0 fs/jfs/jfs_umount.c:124 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:769 kill_block_super+0x44/0xa0 fs/super.c:1918 deactivate_locked_super+0xbc/0x110 fs/super.c:603 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 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:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802952c000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 8 bytes inside of freed 256-byte region [ffff88802952c000, ffff88802952c100) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2952c 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 ffff88813ffbab40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813ffbab40 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000001 ffffffffffffff81 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 5894, tgid 5894 (syz-executor), ts 139083816439 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2591/0x2600 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x230/0x5c0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab+0x7d/0x620 mm/slub.c:3462 new_slab mm/slub.c:3513 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7410 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x339/0x690 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __kmalloc_cache_noprof+0x46f/0x680 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] kset_create lib/kobject.c:969 [inline] kset_create_and_add+0x5a/0x180 lib/kobject.c:1012 register_queue_kobjects net/core/net-sysfs.c:2085 [inline] netdev_register_kobject+0x1c1/0x350 net/core/net-sysfs.c:2344 register_netdevice+0x1455/0x1ed0 net/core/dev.c:11503 rtnl_newlink_create+0x314/0x7b0 net/core/rtnetlink.c:3971 __rtnl_newlink net/core/rtnetlink.c:4098 [inline] rtnl_newlink+0x166d/0x1c30 net/core/rtnetlink.c:4215 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 page last free pid 5954 tgid 5954 ts 139034428773 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xf8e/0x1070 mm/page_alloc.c:2962 mm_free_pgd kernel/fork.c:591 [inline] __mmdrop+0xf3/0x480 kernel/fork.c:734 exit_mm+0x186/0x240 kernel/exit.c:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 __do_sys_exit_group kernel/exit.c:1162 [inline] __se_sys_exit_group kernel/exit.c:1160 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1160 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88802952bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802952bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802952c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802952c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802952c100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================