================================================================== BUG: KASAN: use-after-free in jfs_lazycommit+0x786/0xb60 fs/jfs/jfs_txnmgr.c:2770 Read of size 4 at addr ffff888029742094 by task jfsCommit/275 CPU: 1 PID: 275 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 jfs_lazycommit+0x786/0xb60 fs/jfs/jfs_txnmgr.c:2770 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 4830: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] jfs_fill_super+0xdc/0xb10 fs/jfs/super.c:500 mount_bdev+0x28a/0x3c0 fs/super.c:1411 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1541 do_new_mount+0x247/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 4190: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1438 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:184 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 kvfree_call_rcu+0x105/0x7f0 kernel/rcu/tree.c:3600 drop_sysctl_table+0x359/0x4e0 fs/proc/proc_sysctl.c:1685 drop_sysctl_table+0x348/0x4e0 fs/proc/proc_sysctl.c:1688 unregister_sysctl_table+0x87/0x130 fs/proc/proc_sysctl.c:1723 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7158 [inline] addrconf_exit_net+0x146/0x1e0 net/ipv6/addrconf.c:7267 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x703/0xba0 net/core/net_namespace.c:635 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff888029742000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of 256-byte region [ffff888029742000, ffff888029742100) The buggy address belongs to the page: page:ffffea0000a5d080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29742 head:ffffea0000a5d080 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000b2e200 0000000800000008 ffff888017841b40 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4374, ts 69476164427, free_ts 69272336612 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x11d/0x340 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] new_dir fs/proc/proc_sysctl.c:959 [inline] get_subdir fs/proc/proc_sysctl.c:1004 [inline] __register_sysctl_table+0xa32/0x1240 fs/proc/proc_sysctl.c:1353 __addrconf_sysctl_register+0x271/0x3e0 net/ipv6/addrconf.c:7129 addrconf_init_net+0x359/0x5a0 net/ipv6/addrconf.c:7240 ops_init+0x360/0x5f0 net/core/net_namespace.c:138 setup_net+0x39e/0xa10 net/core/net_namespace.c:333 copy_net_ns+0x33e/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110 copy_namespaces+0x378/0x3d0 kernel/nsproxy.c:178 copy_process+0x17f0/0x3e70 kernel/fork.c:2295 kernel_clone+0x23f/0x990 kernel/fork.c:2682 __do_sys_clone kernel/fork.c:2799 [inline] __se_sys_clone kernel/fork.c:2783 [inline] __x64_sys_clone+0x19a/0x210 kernel/fork.c:2783 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238 getname_flags+0xb7/0x4f0 fs/namei.c:138 do_sys_openat2+0xdd/0x500 fs/open.c:1249 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888029741f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888029742000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888029742080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888029742100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888029742180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================