================================================================== BUG: KASAN: slab-use-after-free in __list_lru_walk_one+0xfb/0x420 mm/list_lru.c:293 Read of size 8 at addr ffff888077e31078 by task syz.7.5081/927 CPU: 0 UID: 0 PID: 927 Comm: syz.7.5081 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __list_lru_walk_one+0xfb/0x420 mm/list_lru.c:293 list_lru_walk_one+0x3c/0x50 mm/list_lru.c:341 list_lru_shrink_walk include/linux/list_lru.h:262 [inline] gfs2_qd_shrink_scan+0x155/0x330 fs/gfs2/quota.c:182 do_shrink_slab+0x6df/0x10d0 mm/shrinker.c:437 shrink_slab+0xd74/0x10d0 mm/shrinker.c:664 drop_slab_node mm/vmscan.c:434 [inline] drop_slab+0x14b/0x290 mm/vmscan.c:452 drop_caches_sysctl_handler+0xc7/0x170 fs/drop_caches.c:68 proc_sys_call_handler+0x4cb/0x700 fs/proc/proc_sysctl.c:600 do_iter_readv_writev+0x623/0x8c0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f734678f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7347599038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f73469e6180 RCX: 00007f734678f749 RDX: 0000000000000001 RSI: 00002000000000c0 RDI: 0000000000000006 RBP: 00007f7346813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f73469e6218 R14: 00007f73469e6180 R15: 00007ffc955050d8 Allocated by task 768: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270 qd_alloc+0x50/0x250 fs/gfs2/quota.c:234 gfs2_quota_init+0x762/0x1200 fs/gfs2/quota.c:1448 gfs2_make_fs_rw+0x143/0x220 fs/gfs2/super.c:149 gfs2_fill_super+0x1b6a/0x21b0 fs/gfs2/ops_fstype.c:1275 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3712 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 768: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kmem_cache_free+0x197/0x620 mm/slub.c:6781 gfs2_qd_dealloc+0x70/0xe0 fs/gfs2/quota.c:111 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xc8e/0x1720 kernel/rcu/tree.c:2857 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] __fib6_clean_all+0x23c/0x380 net/ipv6/ip6_fib.c:2321 rt6_sync_down_dev net/ipv6/route.c:5003 [inline] rt6_disable_ip+0x120/0x720 net/ipv6/route.c:5008 addrconf_ifdown+0x14d/0x1870 net/ipv6/addrconf.c:3853 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] unregister_netdevice_many_notify+0x1867/0x2340 net/core/dev.c:12381 unregister_netdevice_many net/core/dev.c:12444 [inline] unregister_netdevice_queue+0x317/0x350 net/core/dev.c:12258 unregister_netdevice include/linux/netdevice.h:3405 [inline] vxcan_newlink+0x4bd/0x580 drivers/net/can/vxcan.c:250 rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3239 qd_ungrab_sync fs/gfs2/quota.c:493 [inline] gfs2_quota_sync+0x30c/0x460 fs/gfs2/quota.c:1351 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:658 sync_filesystem+0x1cf/0x230 fs/sync.c:66 gfs2_reconfigure+0xbb/0xb20 fs/gfs2/ops_fstype.c:1554 reconfigure_super+0x227/0x880 fs/super.c:1077 do_remount fs/namespace.c:3264 [inline] path_mount+0xd29/0xff0 fs/namespace.c:4014 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888077e31000 which belongs to the cache gfs2_quotad of size 272 The buggy address is located 120 bytes inside of freed 272-byte region [ffff888077e31000, ffff888077e31110) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77e31 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b7e53c0 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800c000c 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x52c50(GFP_NOFS|__GFP_RECLAIMABLE|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 768, tgid 767 (syz.0.5048), ts 1854140962261, free_ts 1845106187305 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xe53/0x1820 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] kmem_cache_alloc_noprof+0x40f/0x710 mm/slub.c:5270 qd_alloc+0x50/0x250 fs/gfs2/quota.c:234 gfs2_quota_init+0x762/0x1200 fs/gfs2/quota.c:1448 gfs2_make_fs_rw+0x143/0x220 fs/gfs2/super.c:149 gfs2_fill_super+0x1b6a/0x21b0 fs/gfs2/ops_fstype.c:1275 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3712 page last free pid 676 tgid 676 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x146/0x170 mm/slub.c:3886 __slab_free+0x294/0x320 mm/slub.c:5952 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270 vm_area_dup+0x2b/0x680 mm/vma_init.c:123 __split_vma+0x1a9/0xa00 mm/vma.c:508 vms_gather_munmap_vmas+0x4c6/0x12f0 mm/vma.c:1383 __mmap_setup mm/vma.c:2366 [inline] __mmap_region mm/vma.c:2690 [inline] mmap_region+0x72b/0x1d10 mm/vma.c:2786 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888077e30f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888077e30f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888077e31000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077e31080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077e31100: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================