================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:197 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:681 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x6cb/0xcc0 kernel/locking/mutex.c:747 Read of size 8 at addr ffff88802e4f8908 by task jfsCommit/111 CPU: 1 PID: 111 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 __mutex_waiter_is_first kernel/locking/mutex.c:197 [inline] __mutex_lock_common kernel/locking/mutex.c:681 [inline] __mutex_lock+0x6cb/0xcc0 kernel/locking/mutex.c:747 jfs_syncpt+0x25/0x90 fs/jfs/jfs_logmgr.c:1039 txEnd+0x2e5/0x520 fs/jfs/jfs_txnmgr.c:549 txLazyCommit fs/jfs/jfs_txnmgr.c:2684 [inline] jfs_lazycommit+0x5a6/0xa60 fs/jfs/jfs_txnmgr.c:2732 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 11603: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] open_inline_log fs/jfs/jfs_logmgr.c:1159 [inline] lmLogOpen+0x2df/0xfb0 fs/jfs/jfs_logmgr.c:1069 jfs_mount_rw+0xea/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x592/0xac0 fs/jfs/super.c:565 mount_bdev+0x22b/0x2d0 fs/super.c:1643 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3377 do_mount fs/namespace.c:3717 [inline] __do_sys_mount fs/namespace.c:3926 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 8815: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 lmLogClose+0x297/0x520 fs/jfs/jfs_logmgr.c:-1 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x134/0x2b0 fs/super.c:693 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88802e4f8800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 264 bytes inside of freed 1024-byte region [ffff88802e4f8800, ffff88802e4f8c00) The buggy address belongs to the physical page: page:ffffea0000b93e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2e4f8 head:ffffea0000b93e00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017841dc0 0000000000000000 dead000000000001 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 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 48, tgid 48 (kworker/u4:3), ts 239794037933, free_ts 239743975773 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2e0 mm/slub.c:2081 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1284 [inline] nlmsg_new include/net/netlink.h:1010 [inline] inet6_rt_notify+0xb4/0x240 net/ipv6/route.c:6236 fib6_add_rt2node net/ipv6/ip6_fib.c:1260 [inline] fib6_add+0x1d9a/0x3d20 net/ipv6/ip6_fib.c:1489 __ip6_ins_rt net/ipv6/route.c:1343 [inline] ip6_route_add+0x8a/0x130 net/ipv6/route.c:3893 addrconf_add_mroute net/ipv6/addrconf.c:2514 [inline] addrconf_add_dev+0x257/0x340 net/ipv6/addrconf.c:2532 addrconf_dev_config net/ipv6/addrconf.c:3451 [inline] addrconf_init_auto_addrs+0x5cc/0xaa0 net/ipv6/addrconf.c:3539 addrconf_notify+0xb62/0x1010 net/ipv6/addrconf.c:3712 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35e/0x410 mm/slub.c:3736 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc_lru+0x115/0x2e0 mm/slub.c:3526 alloc_inode_sb include/linux/fs.h:2946 [inline] sock_alloc_inode+0x28/0xc0 net/socket.c:308 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x63/0x1d0 fs/inode.c:1049 sock_alloc net/socket.c:634 [inline] __sock_create+0x12d/0x940 net/socket.c:1535 sock_create net/socket.c:1627 [inline] __sys_socket_create net/socket.c:1664 [inline] __sys_socket+0xd7/0x1a0 net/socket.c:1715 __do_sys_socket net/socket.c:1729 [inline] __se_sys_socket net/socket.c:1727 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1727 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88802e4f8800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802e4f8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802e4f8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802e4f8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802e4f8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================