CVE-2024-26625
Publication date:
06/03/2024
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
llc: call sock_orphan() at release time<br />
<br />
syzbot reported an interesting trace [1] caused by a stale sk->sk_wq<br />
pointer in a closed llc socket.<br />
<br />
In commit ff7b11aa481f ("net: socket: set sock->sk to NULL after<br />
calling proto_ops::release()") Eric Biggers hinted that some protocols<br />
are missing a sock_orphan(), we need to perform a full audit.<br />
<br />
In net-next, I plan to clear sock->sk from sock_orphan() and<br />
amend Eric patch to add a warning.<br />
<br />
[1]<br />
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]<br />
BUG: KASAN: slab-use-after-free in waitqueue_active include/linux/wait.h:127 [inline]<br />
BUG: KASAN: slab-use-after-free in sock_def_write_space_wfree net/core/sock.c:3384 [inline]<br />
BUG: KASAN: slab-use-after-free in sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468<br />
Read of size 8 at addr ffff88802f4fc880 by task ksoftirqd/1/27<br />
<br />
CPU: 1 PID: 27 Comm: ksoftirqd/1 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0<br />
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014<br />
Call Trace:<br />
<br />
__dump_stack lib/dump_stack.c:88 [inline]<br />
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106<br />
print_address_description mm/kasan/report.c:377 [inline]<br />
print_report+0xc4/0x620 mm/kasan/report.c:488<br />
kasan_report+0xda/0x110 mm/kasan/report.c:601<br />
list_empty include/linux/list.h:373 [inline]<br />
waitqueue_active include/linux/wait.h:127 [inline]<br />
sock_def_write_space_wfree net/core/sock.c:3384 [inline]<br />
sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468<br />
skb_release_head_state+0xa3/0x2b0 net/core/skbuff.c:1080<br />
skb_release_all net/core/skbuff.c:1092 [inline]<br />
napi_consume_skb+0x119/0x2b0 net/core/skbuff.c:1404<br />
e1000_unmap_and_free_tx_resource+0x144/0x200 drivers/net/ethernet/intel/e1000/e1000_main.c:1970<br />
e1000_clean_tx_irq drivers/net/ethernet/intel/e1000/e1000_main.c:3860 [inline]<br />
e1000_clean+0x4a1/0x26e0 drivers/net/ethernet/intel/e1000/e1000_main.c:3801<br />
__napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6576<br />
napi_poll net/core/dev.c:6645 [inline]<br />
net_rx_action+0x956/0xe90 net/core/dev.c:6778<br />
__do_softirq+0x21a/0x8de kernel/softirq.c:553<br />
run_ksoftirqd kernel/softirq.c:921 [inline]<br />
run_ksoftirqd+0x31/0x60 kernel/softirq.c:913<br />
smpboot_thread_fn+0x660/0xa10 kernel/smpboot.c:164<br />
kthread+0x2c6/0x3a0 kernel/kthread.c:388<br />
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147<br />
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242<br />
<br />
<br />
Allocated by task 5167:<br />
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47<br />
kasan_save_track+0x14/0x30 mm/kasan/common.c:68<br />
unpoison_slab_object mm/kasan/common.c:314 [inline]<br />
__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:340<br />
kasan_slab_alloc include/linux/kasan.h:201 [inline]<br />
slab_post_alloc_hook mm/slub.c:3813 [inline]<br />
slab_alloc_node mm/slub.c:3860 [inline]<br />
kmem_cache_alloc_lru+0x142/0x6f0 mm/slub.c:3879<br />
alloc_inode_sb include/linux/fs.h:3019 [inline]<br />
sock_alloc_inode+0x25/0x1c0 net/socket.c:308<br />
alloc_inode+0x5d/0x220 fs/inode.c:260<br />
new_inode_pseudo+0x16/0x80 fs/inode.c:1005<br />
sock_alloc+0x40/0x270 net/socket.c:634<br />
__sock_create+0xbc/0x800 net/socket.c:1535<br />
sock_create net/socket.c:1622 [inline]<br />
__sys_socket_create net/socket.c:1659 [inline]<br />
__sys_socket+0x14c/0x260 net/socket.c:1706<br />
__do_sys_socket net/socket.c:1720 [inline]<br />
__se_sys_socket net/socket.c:1718 [inline]<br />
__x64_sys_socket+0x72/0xb0 net/socket.c:1718<br />
do_syscall_x64 arch/x86/entry/common.c:52 [inline]<br />
do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83<br />
entry_SYSCALL_64_after_hwframe+0x63/0x6b<br />
<br />
Freed by task 0:<br />
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47<br />
kasan_save_track+0x14/0x30 mm/kasan/common.c:68<br />
kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640<br />
poison_slab_object mm/kasan/common.c:241 [inline]<br />
__kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257<br />
kasan_slab_free include/linux/kasan.h:184 [inline]<br />
slab_free_hook mm/slub.c:2121 [inlin<br />
---truncated---
Severity CVSS v4.0: Pending analysis
Last modification:
07/01/2025