CIFS: VFS: \\127.0.0.1 SMB response too short (0 bytes) ================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:642 [inline] BUG: KASAN: use-after-free in string+0x204/0x290 lib/vsprintf.c:724 Read of size 1 at addr ffff8880764fca00 by task cifsd/9840 CPU: 0 PID: 9840 Comm: cifsd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 string_nocheck lib/vsprintf.c:642 [inline] string+0x204/0x290 lib/vsprintf.c:724 vsnprintf+0x10db/0x1c20 lib/vsprintf.c:2811 vscnprintf lib/vsprintf.c:2914 [inline] scnprintf+0xe5/0x180 lib/vsprintf.c:2968 reconn_set_ipaddr_from_hostname+0x112/0x580 fs/cifs/connect.c:107 __cifs_reconnect fs/cifs/connect.c:288 [inline] cifs_reconnect+0x470/0x1350 fs/cifs/connect.c:447 cifs_demultiplex_thread+0x1eca/0x35b0 fs/cifs/connect.c:-1 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 9837: 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+0xaf/0xe0 mm/kasan/common.c:522 kstrdup+0x32/0x70 mm/util.c:60 cifs_get_tcp_session+0xde/0x18f0 fs/cifs/connect.c:1431 mount_get_conns+0xc3/0xe00 fs/cifs/connect.c:2988 is_dfs_mount fs/cifs/connect.c:3354 [inline] cifs_mount+0x162/0x1380 fs/cifs/connect.c:3549 cifs_smb3_do_mount+0x366/0x760 fs/cifs/cifsfs.c:895 smb3_get_tree_common fs/cifs/fs_context.c:708 [inline] smb3_get_tree+0x59a/0xa80 fs/cifs/fs_context.c:726 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x247/0xa40 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 Freed by task 9837: 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+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 cifs_put_tcp_session+0x2e1/0x3d0 fs/cifs/connect.c:1404 mount_put_conns+0xb0/0x270 fs/cifs/connect.c:2969 cifs_mount+0xbf5/0x1380 fs/cifs/connect.c:3597 cifs_smb3_do_mount+0x366/0x760 fs/cifs/cifsfs.c:895 smb3_get_tree_common fs/cifs/fs_context.c:708 [inline] smb3_get_tree+0x59a/0xa80 fs/cifs/fs_context.c:726 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x247/0xa40 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 The buggy address belongs to the object at ffff8880764fca00 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of 16-byte region [ffff8880764fca00, ffff8880764fca10) The buggy address belongs to the page: page:ffffea0001d93f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x764fc flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00006d6600 0000000d0000000d ffff888016c413c0 raw: 0000000000000000 0000000000800080 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 4189, ts 78616301391, free_ts 78601727265 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 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+0x807/0xdd0 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+0x11d/0x340 mm/slub.c:4408 kmalloc_array include/linux/slab.h:647 [inline] kcalloc include/linux/slab.h:676 [inline] mq_init+0x14b/0x650 net/sched/sch_mq.c:83 qdisc_create_dflt+0x11a/0x410 net/sched/sch_generic.c:960 attach_default_qdiscs net/sched/sch_generic.c:1139 [inline] dev_activate+0x192/0x1330 net/sched/sch_generic.c:1193 __dev_open+0x33b/0x430 net/core/dev.c:1559 __dev_change_flags+0x1e4/0x6a0 net/core/dev.c:8879 dev_change_flags+0x78/0x1a0 net/core/dev.c:8950 do_setlink+0xca4/0x29d0 net/core/rtnetlink.c:2793 __rtnl_newlink net/core/rtnetlink.c:3464 [inline] rtnl_newlink+0x15bb/0x1920 net/core/rtnetlink.c:3586 rtnetlink_rcv_msg+0x7f1/0xf10 net/core/rtnetlink.c:5698 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2519 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x78f/0x940 net/netlink/af_netlink.c:1340 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 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] kmem_cache_alloc_node+0x184/0x2c0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] nlmsg_new include/net/netlink.h:964 [inline] netlink_ack+0x35c/0xb10 net/netlink/af_netlink.c:2454 netlink_rcv_skb+0x267/0x430 net/netlink/af_netlink.c:2525 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x78f/0x940 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2073 __do_sys_sendto net/socket.c:2085 [inline] __se_sys_sendto net/socket.c:2081 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2081 Memory state around the buggy address: ffff8880764fc900: fa fb fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc ffff8880764fc980: 00 00 fc fc fa fb fc fc fa fb fc fc fa fb fc fc >ffff8880764fca00: fa fb fc fc 00 00 fc fc fa fb fc fc fa fb fc fc ^ ffff8880764fca80: 00 00 fc fc fa fb fc fc fa fb fc fc fa fb fc fc ffff8880764fcb00: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc ==================================================================