================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x6d7/0xa10 fs/jfs/jfs_txnmgr.c:2737 Read of size 4 at addr ffff888028384894 by task jfsCommit/122 CPU: 0 UID: 0 PID: 122 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 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 jfs_lazycommit+0x6d7/0xa10 fs/jfs/jfs_txnmgr.c:2737 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 8430: 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+0x1f2/0x6b0 mm/slub.c:5780 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] jfs_fill_super+0xc2/0xd80 fs/jfs/super.c:452 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1691 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x329/0xa50 fs/namespace.c:3712 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5803: 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:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x1bb/0x8f0 mm/slub.c:6882 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1722 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1318 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:44 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75 __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_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888028384800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888028384800, ffff888028384900) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28384 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 ffff88813fea6b40 ffffea00015ae080 dead000000000004 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fea6b40 ffffea00015ae080 dead000000000004 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000001 ffffea0000a0e101 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 1019, tgid 1019 (kworker/u8:6), ts 9591658461, 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:3945 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240 alloc_slab_page mm/slub.c:3077 [inline] allocate_slab+0x7a/0x3a0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xaf8/0x13d0 mm/slub.c:4656 __slab_alloc+0xc5/0x1f0 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_node_noprof+0x1aa/0x6e0 mm/slub.c:5788 kmalloc_node_noprof include/linux/slab.h:983 [inline] blk_alloc_flush_queue+0x7f/0x240 block/blk-flush.c:483 blk_mq_init_hctx block/blk-mq.c:3988 [inline] blk_mq_alloc_and_init_hctx+0x7bd/0xc70 block/blk-mq.c:4523 __blk_mq_realloc_hw_ctxs+0x2bd/0x670 block/blk-mq.c:4570 blk_mq_realloc_hw_ctxs block/blk-mq.c:4607 [inline] blk_mq_init_allocated_queue+0x35c/0x13a0 block/blk-mq.c:4637 blk_mq_alloc_queue+0x1ba/0x2e0 block/blk-mq.c:4419 scsi_alloc_sdev+0x7b0/0xc20 drivers/scsi/scsi_scan.c:339 scsi_probe_and_add_lun+0x200/0x4830 drivers/scsi/scsi_scan.c:1218 __scsi_scan_target+0x1f0/0xe10 drivers/scsi/scsi_scan.c:1789 scsi_scan_channel drivers/scsi/scsi_scan.c:1877 [inline] scsi_scan_host_selected+0x375/0x690 drivers/scsi/scsi_scan.c:1906 page_owner free stack trace missing Memory state around the buggy address: ffff888028384780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888028384800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888028384880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888028384900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888028384980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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