Forwarded: Re: [syzbot] [net?] [virt?] memory leak in __vsock_create (2)

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Subject: Re: [syzbot] [net?] [virt?] memory leak in __vsock_create (2)
Author: phind.uet@xxxxxxxxx

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master

On Sun, Jul 19, 2026 at 3:47 PM syzbot
<syzbot+1b2c9c4a0f8708082678@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> memory leak in __vsock_create
>
> 2026/07/19 07:45:48 executed programs: 5
> BUG: memory leak
> unreferenced object 0xffff888113812d00 (size 1272):
>   comm "kworker/1:2", pid 3105, jiffies 4294947499
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     28 00 0b 40 00 00 00 00 00 00 00 00 00 00 00 00  (..@............
>   backtrace (crc 3df84e77):
>     kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>     slab_post_alloc_hook mm/slub.c:4593 [inline]
>     slab_alloc_node mm/slub.c:4893 [inline]
>     kmem_cache_alloc_noprof+0x388/0x410 mm/slub.c:4907
>     sk_prot_alloc+0x3e/0x1b0 net/core/sock.c:2246
>     sk_alloc+0x36/0x3d0 net/core/sock.c:2308
>     __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:919
>     virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1555 [inline]
>     virtio_transport_recv_pkt+0x904/0xf80 net/vmw_vsock/virtio_transport_common.c:1681
>     vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
>     process_one_work+0x2b8/0x600 kernel/workqueue.c:3375
>     process_scheduled_works kernel/workqueue.c:3458 [inline]
>     worker_thread+0x255/0x4a0 kernel/workqueue.c:3539
>     kthread+0x14e/0x1a0 kernel/kthread.c:436
>     ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
>     ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> BUG: memory leak
> unreferenced object 0xffff888117aa8980 (size 32):
>   comm "kworker/1:2", pid 3105, jiffies 4294947499
>   hex dump (first 32 bytes):
>     f8 52 0a 00 81 88 ff ff 00 00 00 00 00 00 00 00  .R..............
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace (crc 42a7bc0e):
>     kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>     slab_post_alloc_hook mm/slub.c:4593 [inline]
>     slab_alloc_node mm/slub.c:4893 [inline]
>     __do_kmalloc_node mm/slub.c:5310 [inline]
>     __kmalloc_noprof+0x3f8/0x540 mm/slub.c:5336
>     _kmalloc_noprof include/linux/slab.h:988 [inline]
>     _kzalloc_noprof include/linux/slab.h:1305 [inline]
>     lsm_blob_alloc+0x4d/0x80 security/security.c:218
>     lsm_sock_alloc security/security.c:4477 [inline]
>     security_sk_alloc+0x2d/0x290 security/security.c:4493
>     sk_prot_alloc+0x8f/0x1b0 net/core/sock.c:2255
>     sk_alloc+0x36/0x3d0 net/core/sock.c:2308
>     __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:919
>     virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1555 [inline]
>     virtio_transport_recv_pkt+0x904/0xf80 net/vmw_vsock/virtio_transport_common.c:1681
>     vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
>     process_one_work+0x2b8/0x600 kernel/workqueue.c:3375
>     process_scheduled_works kernel/workqueue.c:3458 [inline]
>     worker_thread+0x255/0x4a0 kernel/workqueue.c:3539
>     kthread+0x14e/0x1a0 kernel/kthread.c:436
>     ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
>     ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> BUG: memory leak
> unreferenced object 0xffff8881122fe5a0 (size 96):
>   comm "kworker/1:2", pid 3105, jiffies 4294947499
>   hex dump (first 32 bytes):
>     00 2d 81 13 81 88 ff ff 00 00 00 00 00 00 00 00  .-..............
>     00 00 00 00 00 00 00 00 00 00 04 00 00 00 00 00  ................
>   backtrace (crc 159c7144):
>     kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>     slab_post_alloc_hook mm/slub.c:4593 [inline]
>     slab_alloc_node mm/slub.c:4893 [inline]
>     __kmalloc_cache_noprof+0x38c/0x420 mm/slub.c:5456
>     _kmalloc_noprof include/linux/slab.h:984 [inline]
>     _kzalloc_noprof include/linux/slab.h:1305 [inline]
>     virtio_transport_do_socket_init+0x2b/0xf0 net/vmw_vsock/virtio_transport_common.c:907
>     vsock_assign_transport+0x3a3/0x460 net/vmw_vsock/af_vsock.c:670
>     virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1571 [inline]
>     virtio_transport_recv_pkt+0x95c/0xf80 net/vmw_vsock/virtio_transport_common.c:1681
>     vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
>     process_one_work+0x2b8/0x600 kernel/workqueue.c:3375
>     process_scheduled_works kernel/workqueue.c:3458 [inline]
>     worker_thread+0x255/0x4a0 kernel/workqueue.c:3539
>     kthread+0x14e/0x1a0 kernel/kthread.c:436
>     ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
>     ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> BUG: memory leak
> unreferenced object 0xffff888113812800 (size 1272):
>   comm "kworker/1:2", pid 3105, jiffies 4294947499
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     28 00 0b 40 00 00 00 00 00 00 00 00 00 00 00 00  (..@............
>   backtrace (crc 4993b404):
>     kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>     slab_post_alloc_hook mm/slub.c:4593 [inline]
>     slab_alloc_node mm/slub.c:4893 [inline]
>     kmem_cache_alloc_noprof+0x388/0x410 mm/slub.c:4907
>     sk_prot_alloc+0x3e/0x1b0 net/core/sock.c:2246
>     sk_alloc+0x36/0x3d0 net/core/sock.c:2308
>     __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:919
>     virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1555 [inline]
>     virtio_transport_recv_pkt+0x904/0xf80 net/vmw_vsock/virtio_transport_common.c:1681
>     vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
>     process_one_work+0x2b8/0x600 kernel/workqueue.c:3375
>     process_scheduled_works kernel/workqueue.c:3458 [inline]
>     worker_thread+0x255/0x4a0 kernel/workqueue.c:3539
>     kthread+0x14e/0x1a0 kernel/kthread.c:436
>     ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
>     ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> BUG: memory leak
> unreferenced object 0xffff888117aa8320 (size 32):
>   comm "kworker/1:2", pid 3105, jiffies 4294947499
>   hex dump (first 32 bytes):
>     f8 52 0a 00 81 88 ff ff 00 00 00 00 00 00 00 00  .R..............
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace (crc 42a7bc0e):
>     kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>     slab_post_alloc_hook mm/slub.c:4593 [inline]
>     slab_alloc_node mm/slub.c:4893 [inline]
>     __do_kmalloc_node mm/slub.c:5310 [inline]
>     __kmalloc_noprof+0x3f8/0x540 mm/slub.c:5336
>     _kmalloc_noprof include/linux/slab.h:988 [inline]
>     _kzalloc_noprof include/linux/slab.h:1305 [inline]
>     lsm_blob_alloc+0x4d/0x80 security/security.c:218
>     lsm_sock_alloc security/security.c:4477 [inline]
>     security_sk_alloc+0x2d/0x290 security/security.c:4493
>     sk_prot_alloc+0x8f/0x1b0 net/core/sock.c:2255
>     sk_alloc+0x36/0x3d0 net/core/sock.c:2308
>     __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:919
>     virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1555 [inline]
>     virtio_transport_recv_pkt+0x904/0xf80 net/vmw_vsock/virtio_transport_common.c:1681
>     vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
>     process_one_work+0x2b8/0x600 kernel/workqueue.c:3375
>     process_scheduled_works kernel/workqueue.c:3458 [inline]
>     worker_thread+0x255/0x4a0 kernel/workqueue.c:3539
>     kthread+0x14e/0x1a0 kernel/kthread.c:436
>     ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
>     ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> BUG: memory leak
> unreferenced object 0xffff88811756a000 (size 96):
>   comm "kworker/1:2", pid 3105, jiffies 4294947499
>   hex dump (first 32 bytes):
>     00 28 81 13 81 88 ff ff 00 00 00 00 00 00 00 00  .(..............
>     00 00 00 00 00 00 00 00 00 00 04 00 00 00 00 00  ................
>   backtrace (crc 87703aa0):
>     kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>     slab_post_alloc_hook mm/slub.c:4593 [inline]
>     slab_alloc_node mm/slub.c:4893 [inline]
>     __kmalloc_cache_noprof+0x38c/0x420 mm/slub.c:5456
>     _kmalloc_noprof include/linux/slab.h:984 [inline]
>     _kzalloc_noprof include/linux/slab.h:1305 [inline]
>     virtio_transport_do_socket_init+0x2b/0xf0 net/vmw_vsock/virtio_transport_common.c:907
>     vsock_assign_transport+0x3a3/0x460 net/vmw_vsock/af_vsock.c:670
>     virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1571 [inline]
>     virtio_transport_recv_pkt+0x95c/0xf80 net/vmw_vsock/virtio_transport_common.c:1681
>     vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
>     process_one_work+0x2b8/0x600 kernel/workqueue.c:3375
>     process_scheduled_works kernel/workqueue.c:3458 [inline]
>     worker_thread+0x255/0x4a0 kernel/workqueue.c:3539
>     kthread+0x14e/0x1a0 kernel/kthread.c:436
>     ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
>     ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF
>
>
> Tested on:
>
> commit:         0718283a Add linux-next specific files for 20260717
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=13c222b9580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=f74727dd1edec112
> dashboard link: https://syzkaller.appspot.com/bug?extid=1b2c9c4a0f8708082678
> compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
>
> Note: no patches were applied.