================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x771/0xac0 fs/jfs/jfs_txnmgr.c:2738 Read of size 4 at addr ffff88804a947a94 by task jfsCommit/123 CPU: 0 UID: 0 PID: 123 Comm: jfsCommit Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 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 jfs_lazycommit+0x771/0xac0 fs/jfs/jfs_txnmgr.c:2738 kthread+0x38b/0x480 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 12243: 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:409 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x31c/0x600 mm/slub.c:5680 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] jfs_fill_super+0xc2/0xda0 fs/jfs/super.c:452 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1883 vfs_get_tree+0x92/0x2a0 fs/super.c:1943 fc_mount fs/namespace.c:1209 [inline] do_new_mount_fc fs/namespace.c:3785 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3861 do_mount fs/namespace.c:4194 [inline] __do_sys_mount fs/namespace.c:4407 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4384 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 5623: 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:264 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2780 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x1c5/0x650 mm/slub.c:6923 generic_shutdown_super+0x13d/0x2d0 fs/super.c:751 kill_block_super+0x44/0xa0 fs/super.c:1914 deactivate_locked_super+0xbe/0x110 fs/super.c:586 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1329 task_work_run+0x1d9/0x260 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: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:343 [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 ffff88804a947a00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff88804a947a00, ffff88804a947b00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88804a946400 pfn:0x4a946 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b041b40 ffffea0001301110 ffffea0001ecbb10 raw: ffff88804a946400 000000000010000c 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b041b40 ffffea0001301110 ffffea0001ecbb10 head: ffff88804a946400 000000000010000c 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffffffffffff81 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 11808, tgid 11807 (syz.5.1653), ts 587328457269 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1854 prep_new_page mm/page_alloc.c:1862 [inline] get_page_from_freelist+0x220f/0x2280 mm/page_alloc.c:3933 __alloc_frozen_pages_noprof+0x1fc/0x400 mm/page_alloc.c:5471 alloc_slab_page mm/slub.c:3384 [inline] allocate_slab+0x7d/0x5e0 mm/slub.c:3499 new_slab mm/slub.c:3550 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7539 refill_sheaf mm/slub.c:2917 [inline] __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4811 alloc_from_pcs mm/slub.c:4887 [inline] slab_alloc_node mm/slub.c:5021 [inline] __do_kmalloc_node mm/slub.c:5530 [inline] __kmalloc_noprof+0x476/0x710 mm/slub.c:5556 _kmalloc_noprof include/linux/slab.h:995 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] hash_ipportnet6_add+0x2608/0x3290 net/netfilter/ipset/ip_set_hash_gen.h:1093 hash_ipportnet6_uadt+0xa57/0xde0 net/netfilter/ipset/ip_set_hash_ipportnet.c:507 call_ad+0x360/0xb50 net/netfilter/ipset/ip_set_core.c:1771 ip_set_ad+0x82a/0x9d0 net/netfilter/ipset/ip_set_core.c:1861 nfnetlink_rcv_msg+0xcc2/0x12b0 net/netfilter/nfnetlink.c:300 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 nfnetlink_rcv+0x2b9/0x28c0 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x7c3/0xae0 net/netlink/af_netlink.c:1916 page last free pid 11591 tgid 11591 ts 569745223294 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1401 [inline] __free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2952 __slab_free+0x269/0x2c0 mm/slub.c:5926 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4720 [inline] slab_alloc_node mm/slub.c:5033 [inline] kmem_cache_alloc_noprof+0x2b4/0x600 mm/slub.c:5047 vm_area_alloc+0x24/0x140 mm/vma_init.c:36 __mmap_new_vma mm/vma.c:2685 [inline] __mmap_region mm/vma.c:3036 [inline] mmap_region+0x18df/0x2c60 mm/vma.c:3118 do_mmap+0xe0a/0x1300 mm/mmap.c:573 vm_mmap_pgoff+0x272/0x4e0 mm/util.c:581 ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:619 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: ffff88804a947980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804a947a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804a947a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804a947b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804a947b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================