================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x6d9/0xa10 fs/jfs/jfs_txnmgr.c:2736 Read of size 4 at addr ffff8880332ab894 by task jfsCommit/120 CPU: 0 UID: 0 PID: 120 Comm: jfsCommit Tainted: G W syzkaller #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+0x70e/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 7019: 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+0x40b/0x4d0 fs/super.c:1692 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4324 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 6374: 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+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1766 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 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 ffff8880332ab800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff8880332ab800, ffff8880332ab900) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x332aa 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 ffffea00009e6c00 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff888019841b40 ffffea00009e6c00 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000001 ffffea0000ccaa81 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 1, tgid 1 (swapper/0), ts 17314281033, free_ts 0 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_node_track_caller_noprof+0x14c/0x450 mm/slub.c:4384 __do_krealloc mm/slub.c:4942 [inline] krealloc_noprof+0x124/0x340 mm/slub.c:4995 add_sysfs_param+0xc9/0xa20 kernel/params.c:654 kernel_add_sysfs_param+0x7f/0xe0 kernel/params.c:811 param_sysfs_builtin+0x18a/0x230 kernel/params.c:850 param_sysfs_builtin_init+0x23/0x30 kernel/params.c:986 do_one_initcall+0x233/0x820 init/main.c:1269 do_initcall_level+0x104/0x190 init/main.c:1331 do_initcalls+0x59/0xa0 init/main.c:1347 kernel_init_freeable+0x334/0x4b0 init/main.c:1579 page_owner free stack trace missing Memory state around the buggy address: ffff8880332ab780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880332ab800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880332ab880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880332ab900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880332ab980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================