================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x6d9/0xa10 fs/jfs/jfs_txnmgr.c:2737 Read of size 4 at addr ffff88803372aa94 by task jfsCommit/121 CPU: 0 UID: 0 PID: 121 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:2737 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 10063: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x1fb/0x6d0 mm/slub.c:5771 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+0x40e/0x4d0 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+0x302/0xa10 fs/namespace.c:3712 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 9594: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kfree+0x1bd/0x900 mm/slub.c:6871 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+0x425/0x4c0 fs/namespace.c:1318 task_work_run+0x1d4/0x260 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+0xff/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803372aa00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff88803372aa00, ffff88803372ab00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3372a 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 ffff88813ff26b40 ffffea0000a30780 dead000000000004 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813ff26b40 ffffea0000a30780 dead000000000004 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000001 ffffea0000cdca81 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5174, tgid 5174 (udevadm), ts 26892500881, free_ts 26832286273 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xb10/0x1400 mm/slub.c:4651 __slab_alloc+0xc6/0x1f0 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] __kmalloc_cache_noprof+0x101/0x6d0 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] smk_fetch+0x95/0x140 security/smack/smack_lsm.c:285 smack_d_instantiate+0x6f4/0x930 security/smack/smack_lsm.c:3653 security_d_instantiate+0x10a/0x200 security/security.c:3601 d_splice_alias_ops+0x71/0x370 fs/dcache.c:3064 lookup_open fs/namei.c:4413 [inline] open_last_lookups fs/namei.c:4540 [inline] path_openat+0x13aa/0x3df0 fs/namei.c:4784 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 page last free pid 5174 tgid 5174 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xfe1/0x1170 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x149/0x170 mm/slub.c:3886 __slab_free+0x139/0x210 mm/slub.c:5947 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5265 skb_clone+0x212/0x3a0 net/core/skbuff.c:2087 do_one_broadcast net/netlink/af_netlink.c:1455 [inline] netlink_broadcast_filtered+0x6a8/0x1000 net/netlink/af_netlink.c:1533 netlink_broadcast+0x37/0x50 net/netlink/af_netlink.c:1557 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] kobject_uevent_net_broadcast+0x37b/0x560 lib/kobject_uevent.c:410 kobject_uevent_env+0x55e/0x8c0 lib/kobject_uevent.c:608 kobject_synth_uevent+0x527/0xb00 lib/kobject_uevent.c:207 store_uevent+0x16/0x30 kernel/module/main.c:994 module_attr_store+0x65/0x90 kernel/params.c:919 kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352 Memory state around the buggy address: ffff88803372a980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803372aa00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803372aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803372ab00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803372ab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================