[syzbot] [lsm?] memory leak in prepare_creds (7)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 11028ab62899 Merge tag 'probes-fixes-v7.2-rc5' of git://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=140471b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ba7c2d1679fb08a2
dashboard link: https://syzkaller.appspot.com/bug?extid=53515d23498d641e21ea
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1759d9b9580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=122d4aea580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b677b453b580/disk-11028ab6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eec6e520d498/vmlinux-11028ab6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/03c59bb4309c/bzImage-11028ab6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+53515d...@syzkaller.appspotmail.com

2026/07/30 13:50:02 executed programs: 5
BUG: memory leak
unreferenced object 0xffff88810ab2c540 (size 184):
comm "syz-executor", pid 5809, jiffies 4294943975
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 706c7ae4):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4597 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x34f/0x440 mm/slub.c:4931
prepare_creds+0x22/0x570 kernel/cred.c:185
copy_creds+0x44/0x290 kernel/cred.c:286
copy_process+0x988/0x2d70 kernel/fork.c:2153
kernel_clone+0x101/0x710 kernel/fork.c:2748
__do_sys_clone+0x7f/0xb0 kernel/fork.c:2889
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf8/0x610 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff8881021256c0 (size 32):
comm "syz-executor", pid 5809, jiffies 4294943975
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
f8 52 0a 00 81 88 ff ff 00 00 00 00 00 00 00 00 .R..............
backtrace (crc 9ae86290):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4597 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
__do_kmalloc_node mm/slub.c:5333 [inline]
__kmalloc_noprof+0x3bf/0x550 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
lsm_blob_alloc+0x4d/0x80 security/security.c:218
lsm_cred_alloc security/security.c:235 [inline]
security_prepare_creds+0x2d/0x290 security/security.c:2866
prepare_creds+0x317/0x570 kernel/cred.c:215
copy_creds+0x44/0x290 kernel/cred.c:286
copy_process+0x988/0x2d70 kernel/fork.c:2153
kernel_clone+0x101/0x710 kernel/fork.c:2748
__do_sys_clone+0x7f/0xb0 kernel/fork.c:2889
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf8/0x610 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff8881068d2d00 (size 1272):
comm "kworker/1:2", pid 2174, jiffies 4294943976
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 ff0fde65):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4597 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x34f/0x440 mm/slub.c:4931
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:1721 [inline]
virtio_transport_recv_pkt+0x8fa/0x16c0 net/vmw_vsock/virtio_transport_common.c:1847
vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
process_one_work+0x277/0x5a0 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3486
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 0xffff8881145bbb60 (size 32):
comm "kworker/1:2", pid 2174, jiffies 4294943976
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:4597 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
__do_kmalloc_node mm/slub.c:5333 [inline]
__kmalloc_noprof+0x3bf/0x550 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
lsm_blob_alloc+0x4d/0x80 security/security.c:218
lsm_sock_alloc security/security.c:4478 [inline]
security_sk_alloc+0x2d/0x290 security/security.c:4494
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:1721 [inline]
virtio_transport_recv_pkt+0x8fa/0x16c0 net/vmw_vsock/virtio_transport_common.c:1847
vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
process_one_work+0x277/0x5a0 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3486
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 0xffff88811573e0c0 (size 96):
comm "kworker/1:2", pid 2174, jiffies 4294943976
hex dump (first 32 bytes):
00 2d 8d 06 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 af6af911):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4597 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
__kmalloc_cache_noprof+0x356/0x440 mm/slub.c:5485
_kmalloc_noprof include/linux/slab.h:988 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
virtio_transport_do_socket_init+0x2b/0xf0 net/vmw_vsock/virtio_transport_common.c:1056
vsock_assign_transport+0x3a3/0x460 net/vmw_vsock/af_vsock.c:670
virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1737 [inline]
virtio_transport_recv_pkt+0x956/0x16c0 net/vmw_vsock/virtio_transport_common.c:1847
vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
process_one_work+0x277/0x5a0 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3486
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 0xffff8881068d2800 (size 1272):
comm "kworker/1:2", pid 2174, jiffies 4294943977
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 e503b7a6):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4597 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x34f/0x440 mm/slub.c:4931
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:1721 [inline]
virtio_transport_recv_pkt+0x8fa/0x16c0 net/vmw_vsock/virtio_transport_common.c:1847
vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
process_one_work+0x277/0x5a0 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3486
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


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