================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x107/0x7c40 kernel/locking/lockdep.c:4933 Read of size 8 at addr ffff88807807cbb0 by task gfs2_quotad/7868 CPU: 0 PID: 7868 Comm: gfs2_quotad Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 __lock_acquire+0x107/0x7c40 kernel/locking/lockdep.c:4933 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676 __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+0xbb/0x1c0 kernel/sched/wait.c:410 gfs2_quotad+0x501/0x690 fs/gfs2/quota.c:1579 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 8462: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node_track_caller+0xb0/0x240 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x226/0x7d0 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1303 [inline] alloc_skb_with_frags+0xa7/0x710 net/core/skbuff.c:6186 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2763 packet_alloc_skb net/packet/af_packet.c:3006 [inline] packet_snd net/packet/af_packet.c:3102 [inline] packet_sendmsg+0x31b9/0x4c30 net/packet/af_packet.c:3191 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x497/0x650 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 8462: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3700 skb_free_head net/core/skbuff.c:762 [inline] pskb_expand_head+0x417/0x13a0 net/core/skbuff.c:1881 __pskb_pull_tail+0xae/0x14c0 net/core/skbuff.c:2396 __skb_linearize include/linux/skbuff.h:3777 [inline] validate_xmit_skb+0x58d/0xe80 net/core/dev.c:3791 __dev_queue_xmit+0x159a/0x3810 net/core/dev.c:4365 packet_snd net/packet/af_packet.c:3160 [inline] packet_sendmsg+0x3a9e/0x4c30 net/packet/af_packet.c:3191 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x497/0x650 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x14f/0x950 kernel/rcu/tree.c:2849 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7c/0xe0 fs/super.c:1481 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x471/0x4f0 fs/namespace.c:1191 task_work_run+0x1d0/0x260 kernel/task_work.c:203 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+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807807c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2992 bytes inside of 8192-byte region [ffff88807807c000, ffff88807807e000) The buggy address belongs to the physical page: page:ffffea0001e01e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78078 head:ffffea0001e01e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000b06200 dead000000000004 ffff888017442280 raw: 0000000000000000 0000000000020002 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 6851, tgid 6849 (syz.0.937), ts 214233953464, free_ts 213575652364 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa3/0x240 mm/slab_common.c:949 kmalloc_array include/linux/slab.h:615 [inline] mb_cache_create+0x159/0x510 fs/mbcache.c:370 __ext4_fill_super fs/ext4/super.c:5405 [inline] ext4_fill_super+0x5841/0x78f0 fs/ext4/super.c:5693 get_tree_bdev+0x3e6/0x610 fs/super.c:1377 vfs_get_tree+0x88/0x270 fs/super.c:1584 do_new_mount+0x247/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] kmem_cache_alloc_node+0x1ad/0x310 mm/slub.c:3404 __alloc_skb+0xf9/0x7d0 net/core/skbuff.c:505 alloc_skb_fclone include/linux/skbuff.h:1353 [inline] tcp_stream_alloc_skb+0x3e/0x330 net/ipv4/tcp.c:873 tcp_sendmsg_locked+0xca4/0x39e0 net/ipv4/tcp.c:1336 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1494 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] sock_write_iter+0x2d5/0x3e0 net/socket.c:1144 call_write_iter include/linux/fs.h:2271 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x482/0x9a0 fs/read_write.c:584 ksys_write+0x14d/0x260 fs/read_write.c:637 Memory state around the buggy address: ffff88807807ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807807cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807807cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807807cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807807cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================