CVE-2024-26625

In the Linux kernel, the following vulnerability has been resolved:

llc: call sock_orphan() at release time

syzbot reported an interesting trace [1] caused by a stale sk->sk_wq

pointer in a closed llc socket.

In commit ff7b11aa481f ("net: socket: set sock->sk to NULL after

calling proto_ops::release()") Eric Biggers hinted that some protocols

are missing a sock_orphan(), we need to perform a full audit.

In net-next, I plan to clear sock->sk from sock_orphan() and

amend Eric patch to add a warning.

[1]

BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]

BUG: KASAN: slab-use-after-free in waitqueue_active include/linux/wait.h:127 [inline]

BUG: KASAN: slab-use-after-free in sock_def_write_space_wfree net/core/sock.c:3384 [inline]

BUG: KASAN: slab-use-after-free in sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468

Read of size 8 at addr ffff88802f4fc880 by task ksoftirqd/1/27

CPU: 1 PID: 27 Comm: ksoftirqd/1 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014

Call Trace:

<TASK>

__dump_stack lib/dump_stack.c:88 [inline]

dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106

print_address_description mm/kasan/report.c:377 [inline]

print_report+0xc4/0x620 mm/kasan/report.c:488

kasan_report+0xda/0x110 mm/kasan/report.c:601

list_empty include/linux/list.h:373 [inline]

waitqueue_active include/linux/wait.h:127 [inline]

sock_def_write_space_wfree net/core/sock.c:3384 [inline]

sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468

skb_release_head_state+0xa3/0x2b0 net/core/skbuff.c:1080

skb_release_all net/core/skbuff.c:1092 [inline]

napi_consume_skb+0x119/0x2b0 net/core/skbuff.c:1404

e1000_unmap_and_free_tx_resource+0x144/0x200 drivers/net/ethernet/intel/e1000/e1000_main.c:1970

e1000_clean_tx_irq drivers/net/ethernet/intel/e1000/e1000_main.c:3860 [inline]

e1000_clean+0x4a1/0x26e0 drivers/net/ethernet/intel/e1000/e1000_main.c:3801

__napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6576

napi_poll net/core/dev.c:6645 [inline]

net_rx_action+0x956/0xe90 net/core/dev.c:6778

__do_softirq+0x21a/0x8de kernel/softirq.c:553

run_ksoftirqd kernel/softirq.c:921 [inline]

run_ksoftirqd+0x31/0x60 kernel/softirq.c:913

smpboot_thread_fn+0x660/0xa10 kernel/smpboot.c:164

kthread+0x2c6/0x3a0 kernel/kthread.c:388

ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147

ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

</TASK>

Allocated by task 5167:

kasan_save_stack+0x33/0x50 mm/kasan/common.c:47

kasan_save_track+0x14/0x30 mm/kasan/common.c:68

unpoison_slab_object mm/kasan/common.c:314 [inline]

__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:340

kasan_slab_alloc include/linux/kasan.h:201 [inline]

slab_post_alloc_hook mm/slub.c:3813 [inline]

slab_alloc_node mm/slub.c:3860 [inline]

kmem_cache_alloc_lru+0x142/0x6f0 mm/slub.c:3879

alloc_inode_sb include/linux/fs.h:3019 [inline]

sock_alloc_inode+0x25/0x1c0 net/socket.c:308

alloc_inode+0x5d/0x220 fs/inode.c:260

new_inode_pseudo+0x16/0x80 fs/inode.c:1005

sock_alloc+0x40/0x270 net/socket.c:634

__sock_create+0xbc/0x800 net/socket.c:1535

sock_create net/socket.c:1622 [inline]

__sys_socket_create net/socket.c:1659 [inline]

__sys_socket+0x14c/0x260 net/socket.c:1706

__do_sys_socket net/socket.c:1720 [inline]

__se_sys_socket net/socket.c:1718 [inline]

__x64_sys_socket+0x72/0xb0 net/socket.c:1718

do_syscall_x64 arch/x86/entry/common.c:52 [inline]

do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83

entry_SYSCALL_64_after_hwframe+0x63/0x6b

Freed by task 0:

kasan_save_stack+0x33/0x50 mm/kasan/common.c:47

kasan_save_track+0x14/0x30 mm/kasan/common.c:68

kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640

poison_slab_object mm/kasan/common.c:241 [inline]

__kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257

kasan_slab_free include/linux/kasan.h:184 [inline]

slab_free_hook mm/slub.c:2121 [inlin

---truncated---