================================================================== BUG: KASAN: use-after-free in ext4_get_inode_usage+0x39c/0x520 fs/ext4/xattr.c:821 Read of size 4 at addr ffff88812141a070 by task syz.2.26/431 CPU: 0 PID: 431 Comm: syz.2.26 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 do_fchownat+0x147/0x240 fs/open.c:768 __do_sys_lchown fs/open.c:793 [inline] __se_sys_lchown fs/open.c:791 [inline] __x64_sys_lchown+0x85/0x90 fs/open.c:791 x64_sys_call+0x951/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:95 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: 0033:0x7f995499de99 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:00007f99557a8028 EFLAGS: 00000246 ORIG_RAX: 000000000000005e RAX: ffffffffffffffda RBX: 00007f9954c25fa0 RCX: 00007f995499de99 RDX: 000000000000ee01 RSI: 0000000000000000 RDI: 00002000000006c0 RBP: 00007f9954a33eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9954c26038 R14: 00007f9954c25fa0 R15: 00007ffef270fba8 Allocated by task 259: 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] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x166/0x320 mm/slub.c:3408 skb_clone+0x1e8/0x380 net/core/skbuff.c:1663 dev_queue_xmit_nit+0x245/0xab0 net/core/dev.c:2342 xmit_one net/core/dev.c:3699 [inline] dev_hard_start_xmit+0x15f/0x730 net/core/dev.c:3722 sch_direct_xmit+0x279/0x9c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3943 [inline] __dev_queue_xmit+0x163e/0x3540 net/core/dev.c:4348 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_resolve_output+0x6ee/0x7f0 net/core/neighbour.c:1563 neigh_output include/net/neighbour.h:552 [inline] ip_finish_output2+0xc6e/0xf50 net/ipv4/ip_output.c:228 __ip_finish_output+0x172/0x370 net/ipv4/ip_output.c:-1 ip_finish_output+0x31/0x2b0 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x1ea/0x390 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:453 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x1129/0x1cf0 net/ipv4/ip_output.c:538 ip_queue_xmit+0x4d/0x70 net/ipv4/ip_output.c:552 __tcp_transmit_skb+0x1da6/0x3410 net/ipv4/tcp_output.c:1406 __tcp_send_ack+0x2cf/0x690 net/ipv4/tcp_output.c:4021 tcp_send_ack+0x3b/0x60 net/ipv4/tcp_output.c:4027 __tcp_cleanup_rbuf+0x1e6/0x480 net/ipv4/tcp.c:1626 tcp_cleanup_rbuf net/ipv4/tcp.c:1637 [inline] tcp_recvmsg_locked+0x1b84/0x23c0 net/ipv4/tcp.c:2672 tcp_recvmsg+0x21a/0x820 net/ipv4/tcp.c:2702 inet_recvmsg+0x141/0x480 net/ipv4/af_inet.c:875 sock_recvmsg_nosec net/socket.c:1020 [inline] sock_recvmsg net/socket.c:1038 [inline] sock_read_iter+0x2ee/0x3b0 net/socket.c:1111 call_read_iter include/linux/fs.h:2276 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x46e/0x930 fs/read_write.c:470 ksys_read+0x14a/0x260 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:621 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1 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 259: 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 packet_rcv+0x16d/0x1510 net/packet/af_packet.c:2280 dev_queue_xmit_nit+0xa27/0xab0 net/core/dev.c:2374 xmit_one net/core/dev.c:3699 [inline] dev_hard_start_xmit+0x15f/0x730 net/core/dev.c:3722 sch_direct_xmit+0x279/0x9c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3943 [inline] __dev_queue_xmit+0x163e/0x3540 net/core/dev.c:4348 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_resolve_output+0x6ee/0x7f0 net/core/neighbour.c:1563 neigh_output include/net/neighbour.h:552 [inline] ip_finish_output2+0xc6e/0xf50 net/ipv4/ip_output.c:228 __ip_finish_output+0x172/0x370 net/ipv4/ip_output.c:-1 ip_finish_output+0x31/0x2b0 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x1ea/0x390 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:453 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x1129/0x1cf0 net/ipv4/ip_output.c:538 ip_queue_xmit+0x4d/0x70 net/ipv4/ip_output.c:552 __tcp_transmit_skb+0x1da6/0x3410 net/ipv4/tcp_output.c:1406 __tcp_send_ack+0x2cf/0x690 net/ipv4/tcp_output.c:4021 tcp_send_ack+0x3b/0x60 net/ipv4/tcp_output.c:4027 __tcp_cleanup_rbuf+0x1e6/0x480 net/ipv4/tcp.c:1626 tcp_cleanup_rbuf net/ipv4/tcp.c:1637 [inline] tcp_recvmsg_locked+0x1b84/0x23c0 net/ipv4/tcp.c:2672 tcp_recvmsg+0x21a/0x820 net/ipv4/tcp.c:2702 inet_recvmsg+0x141/0x480 net/ipv4/af_inet.c:875 sock_recvmsg_nosec net/socket.c:1020 [inline] sock_recvmsg net/socket.c:1038 [inline] sock_read_iter+0x2ee/0x3b0 net/socket.c:1111 call_read_iter include/linux/fs.h:2276 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x46e/0x930 fs/read_write.c:470 ksys_read+0x14a/0x260 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:621 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1 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 ffff88812141a000 which belongs to the cache skbuff_head_cache of size 256 The buggy address is located 112 bytes inside of 256-byte region [ffff88812141a000, ffff88812141a100) The buggy address belongs to the physical page: page:ffffea0004850680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12141a flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881001f0180 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 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 259, tgid 259 (sshd-session), ts 18332821321, 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] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x1a8/0x320 mm/slub.c:3408 skb_clone+0x1e8/0x380 net/core/skbuff.c:1663 dev_queue_xmit_nit+0x245/0xab0 net/core/dev.c:2342 xmit_one net/core/dev.c:3699 [inline] dev_hard_start_xmit+0x15f/0x730 net/core/dev.c:3722 sch_direct_xmit+0x279/0x9c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3943 [inline] __dev_queue_xmit+0x163e/0x3540 net/core/dev.c:4348 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_resolve_output+0x6ee/0x7f0 net/core/neighbour.c:1563 neigh_output include/net/neighbour.h:552 [inline] ip_finish_output2+0xc6e/0xf50 net/ipv4/ip_output.c:228 page_owner free stack trace missing Memory state around the buggy address: ffff888121419f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888121419f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88812141a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88812141a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88812141a100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================