EXT4-fs: Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE [EXT4 FS bs=1024, gc=1, bpg=131072, ipg=32, mo=e855c01c, mo2=0003] System zones: 0-1, 3-36 EXT4-fs (loop2): mounted filesystem without journal. Quota mode: writeback. ================================================================== BUG: KASAN: use-after-free in ext4_get_inode_usage+0x39c/0x520 fs/ext4/xattr.c:821 Read of size 4 at addr ffff888111fb7070 by task syz.2.17/376 CPU: 1 PID: 376 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 ext4_get_inode_usage+0x39c/0x520 fs/ext4/xattr.c:821 __dquot_transfer+0x1a0/0x2370 fs/quota/dquot.c:2015 dquot_transfer+0x620/0x7d0 fs/quota/dquot.c:2174 ext4_setattr+0xa01/0x1c80 fs/ext4/inode.c:5529 notify_change+0xd33/0x1030 fs/attr.c:499 chown_common+0x448/0x5f0 fs/open.c:737 vfs_fchown fs/open.c:805 [inline] ksys_fchown+0xef/0x160 fs/open.c:816 __do_sys_fchown fs/open.c:824 [inline] __se_sys_fchown fs/open.c:822 [inline] __x64_sys_fchown+0x7a/0x90 fs/open.c:822 x64_sys_call+0x132/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:94 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 RIP: 0033:0x7f4f5539de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdb51c3948 EFLAGS: 00000246 ORIG_RAX: 000000000000005d RAX: ffffffffffffffda RBX: 00007f4f55625fa0 RCX: 00007f4f5539de99 RDX: 000000000000ee01 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f4f55433eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4f55625fac R14: 00007f4f55625fa0 R15: 00007f4f55625fa0 Allocated by task 344: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:334 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] kmem_cache_alloc_node+0x179/0x330 mm/slub.c:3429 __alloc_skb+0xe8/0x4a0 net/core/skbuff.c:508 alloc_skb include/linux/skbuff.h:1322 [inline] alloc_uevent_skb+0x85/0x240 lib/kobject_uevent.c:290 uevent_net_broadcast_tagged lib/kobject_uevent.c:351 [inline] kobject_uevent_net_broadcast+0x1b4/0x5b0 lib/kobject_uevent.c:412 kobject_uevent_env+0x541/0x720 lib/kobject_uevent.c:608 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 device_add+0xa1a/0xec0 drivers/base/core.c:3679 netdev_register_kobject+0x18e/0x330 net/core/net-sysfs.c:2009 register_netdevice+0xec9/0x1550 net/core/dev.c:10206 register_netdev+0x3e/0x50 net/core/dev.c:10332 ip6gre_init_net+0x2b1/0x3b0 net/ipv6/ip6_gre.c:1655 ops_init+0x2ce/0x470 net/core/net_namespace.c:138 setup_net+0x4b4/0xcd0 net/core/net_namespace.c:335 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:481 create_new_namespaces+0x3a8/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4d7/0x820 kernel/fork.c:3426 __do_sys_unshare kernel/fork.c:3509 [inline] __se_sys_unshare kernel/fork.c:3507 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3507 x64_sys_call+0x767/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 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 344: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3737 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:874 [inline] consume_skb+0xb3/0x1f0 net/core/skbuff.c:1038 netlink_broadcast+0x107b/0x1170 net/netlink/af_netlink.c:1522 uevent_net_broadcast_tagged lib/kobject_uevent.c:372 [inline] kobject_uevent_net_broadcast+0x511/0x5b0 lib/kobject_uevent.c:412 kobject_uevent_env+0x541/0x720 lib/kobject_uevent.c:608 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 device_add+0xa1a/0xec0 drivers/base/core.c:3679 netdev_register_kobject+0x18e/0x330 net/core/net-sysfs.c:2009 register_netdevice+0xec9/0x1550 net/core/dev.c:10206 register_netdev+0x3e/0x50 net/core/dev.c:10332 ip6gre_init_net+0x2b1/0x3b0 net/ipv6/ip6_gre.c:1655 ops_init+0x2ce/0x470 net/core/net_namespace.c:138 setup_net+0x4b4/0xcd0 net/core/net_namespace.c:335 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:481 create_new_namespaces+0x3a8/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4d7/0x820 kernel/fork.c:3426 __do_sys_unshare kernel/fork.c:3509 [inline] __se_sys_unshare kernel/fork.c:3507 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3507 x64_sys_call+0x767/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 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 The buggy address belongs to the object at ffff888111fb7000 which belongs to the cache skbuff_head_cache of size 256 The buggy address is located 112 bytes inside of 256-byte region [ffff888111fb7000, ffff888111fb7100) The buggy address belongs to the physical page: page:ffffea000447edc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111fb7 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 dead000000000100 dead000000000122 ffff888108855800 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 103, tgid 103 (udevadm), ts 4959887916, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4586 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5930 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] kmem_cache_alloc_node+0x1ba/0x330 mm/slub.c:3429 __alloc_skb+0xe8/0x4a0 net/core/skbuff.c:508 alloc_skb include/linux/skbuff.h:1322 [inline] alloc_uevent_skb+0x85/0x240 lib/kobject_uevent.c:290 uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline] kobject_uevent_net_broadcast+0x343/0x5b0 lib/kobject_uevent.c:409 kobject_uevent_env+0x541/0x720 lib/kobject_uevent.c:608 kobject_synth_uevent+0x457/0x940 lib/kobject_uevent.c:208 uevent_store+0x4b/0x70 drivers/base/core.c:2693 drv_attr_store+0x88/0xb0 drivers/base/bus.c:77 page_owner free stack trace missing Memory state around the buggy address: ffff888111fb6f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888111fb6f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888111fb7000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888111fb7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111fb7100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================