================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common+0xd0f/0x2400 kernel/locking/mutex.c:671 Read of size 8 at addr ffff8880257df908 by task jfsCommit/276 CPU: 1 PID: 276 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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 __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] __mutex_lock_common+0xd0f/0x2400 kernel/locking/mutex.c:671 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 jfs_syncpt+0x21/0x90 fs/jfs/jfs_logmgr.c:1047 txEnd+0x2e1/0x520 fs/jfs/jfs_txnmgr.c:550 txLazyCommit fs/jfs/jfs_txnmgr.c:2719 [inline] jfs_lazycommit+0x5b8/0xb40 fs/jfs/jfs_txnmgr.c:2767 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 4439: 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+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] open_inline_log fs/jfs/jfs_logmgr.c:1167 [inline] lmLogOpen+0x2c0/0xf90 fs/jfs/jfs_logmgr.c:1077 jfs_mount_rw+0xf8/0x5c0 fs/jfs/jfs_mount.c:253 jfs_fill_super+0x5c1/0xb00 fs/jfs/super.c:570 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/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 4189: 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+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 lmLogClose+0x293/0x520 fs/jfs/jfs_logmgr.c:-1 jfs_umount+0x28f/0x360 fs/jfs/jfs_umount.c:116 jfs_put_super+0x88/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 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:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff8880257df800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 264 bytes inside of 1024-byte region [ffff8880257df800, ffff8880257dfc00) The buggy address belongs to the page: page:ffffea000095f600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x257d8 head:ffffea000095f600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001e09000 0000000400000004 ffff888016c41dc0 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 4243, ts 65917536594, free_ts 65866629894 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 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+0x80a/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+0x1cd/0x330 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] neigh_alloc net/core/neighbour.c:438 [inline] ___neigh_create+0x6d2/0x2250 net/core/neighbour.c:591 ip6_finish_output2+0x9f6/0x1510 net/ipv6/ip6_output.c:127 dst_output include/net/dst.h:452 [inline] NF_HOOK+0x163/0x460 include/linux/netfilter.h:302 mld_sendpack+0x6f2/0xc00 net/ipv6/mcast.c:1825 mld_send_cr net/ipv6/mcast.c:2126 [inline] mld_ifc_work+0x836/0xb40 net/ipv6/mcast.c:2658 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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+0x1a5/0x200 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/0xd0 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+0x100/0x290 mm/slub.c:3238 vm_area_alloc+0x20/0xe0 kernel/fork.c:350 __mmap_region mm/mmap.c:1782 [inline] mmap_region+0xac0/0x1650 mm/mmap.c:2933 do_mmap+0x819/0xe90 mm/mmap.c:1586 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:551 elf_map+0xf9/0x240 fs/binfmt_elf.c:388 load_elf_binary+0x1092/0x28e0 fs/binfmt_elf.c:1141 search_binary_handler fs/exec.c:1742 [inline] exec_binprm fs/exec.c:1783 [inline] bprm_execve+0xaee/0x1840 fs/exec.c:1852 Memory state around the buggy address: ffff8880257df800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880257df880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880257df900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880257df980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880257dfa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================