================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x106/0x7d10 kernel/locking/lockdep.c:4882 Read of size 8 at addr ffff888074440bb0 by task gfs2_quotad/10557 CPU: 0 PID: 10557 Comm: gfs2_quotad Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 __lock_acquire+0x106/0x7d10 kernel/locking/lockdep.c:4882 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 finish_wait+0xb5/0x1d0 kernel/sched/wait.c:407 gfs2_quotad+0x710/0x890 fs/gfs2/quota.c:1605 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 10986: 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_array include/linux/slab.h:647 [inline] kcalloc include/linux/slab.h:676 [inline] cache_create_net+0x8e/0x250 net/sunrpc/cache.c:1748 rsc_cache_create_net net/sunrpc/auth_gss/svcauth_gss.c:1949 [inline] gss_svc_init_net+0x54/0x410 net/sunrpc/auth_gss/svcauth_gss.c:1977 ops_init+0x357/0x600 net/core/net_namespace.c:138 setup_net+0x39e/0xa10 net/core/net_namespace.c:333 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226 ksys_unshare+0x503/0x8c0 kernel/fork.c:3175 __do_sys_unshare kernel/fork.c:3249 [inline] __se_sys_unshare kernel/fork.c:3247 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3247 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 5166: 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 cache_destroy_net+0x32/0x40 net/sunrpc/cache.c:1764 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x706/0xba0 net/core/net_namespace.c:635 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 The buggy address belongs to the object at ffff888074440000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2992 bytes inside of 8192-byte region [ffff888074440000, ffff888074442000) The buggy address belongs to the page: page:ffffea0001d11000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888074444000 pfn:0x74440 head:ffffea0001d11000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001fc4a08 ffffea0000b26408 ffff888016c42280 raw: ffff888074444000 0000000000020001 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 10166, ts 271682069369, free_ts 271681249064 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: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+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_array include/linux/slab.h:647 [inline] mb_cache_create+0x15b/0x530 fs/mbcache.c:407 ext4_fill_super+0x6e51/0x94f0 fs/ext4/super.c:4812 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 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 put_page include/linux/mm.h:1258 [inline] __skb_frag_unref include/linux/skbuff.h:3254 [inline] skb_release_data+0x3b1/0x800 net/core/skbuff.c:672 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb+0x4c/0x60 net/core/skbuff.c:756 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3407 [inline] tcp_ack+0x1ffd/0x61b0 net/ipv4/tcp_input.c:3964 tcp_rcv_established+0x896/0x1ce0 net/ipv4/tcp_input.c:6057 tcp_v4_do_rcv+0x44b/0x9b0 net/ipv4/tcp_ipv4.c:1731 tcp_v4_rcv+0x26d8/0x2d10 net/ipv4/tcp_ipv4.c:2143 ip_protocol_deliver_rcu+0x3ad/0x770 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x1d5/0x320 net/ipv4/ip_input.c:231 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 dst_input include/net/dst.h:462 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:577 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline] ip_sublist_rcv+0xa33/0xd30 net/ipv4/ip_input.c:636 ip_list_rcv+0x3ee/0x440 net/ipv4/ip_input.c:671 __netif_receive_skb_list_ptype net/core/dev.c:5594 [inline] __netif_receive_skb_list_core+0x57f/0x750 net/core/dev.c:5642 __netif_receive_skb_list net/core/dev.c:5694 [inline] netif_receive_skb_list_internal+0x898/0xbd0 net/core/dev.c:5785 gro_normal_list net/core/dev.c:5939 [inline] napi_complete_done+0x378/0x850 net/core/dev.c:6677 Memory state around the buggy address: ffff888074440a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888074440b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888074440b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888074440c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888074440c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================