Subject: CVE-2024-26625: llc: call sock_orphan() at release time

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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 [inline]
  slab_free mm/slub.c:4299 [inline]
  kmem_cache_free+0x129/0x350 mm/slub.c:4363
  i_callback+0x43/0x70 fs/inode.c:249
  rcu_do_batch kernel/rcu/tree.c:2158 [inline]
  rcu_core+0x819/0x1680 kernel/rcu/tree.c:2433
  __do_softirq+0x21a/0x8de kernel/softirq.c:553

Last potentially related work creation:
  kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
  __kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:586
  __call_rcu_common.constprop.0+0x9a/0x7b0 kernel/rcu/tree.c:2683
  destroy_inode+0x129/0x1b0 fs/inode.c:315
  iput_final fs/inode.c:1739 [inline]
  iput.part.0+0x560/0x7b0 fs/inode.c:1765
  iput+0x5c/0x80 fs/inode.c:1755
  dentry_unlink_inode+0x292/0x430 fs/dcache.c:400
  __dentry_kill+0x1ca/0x5f0 fs/dcache.c:603
  dput.part.0+0x4ac/0x9a0 fs/dcache.c:845
  dput+0x1f/0x30 fs/dcache.c:835
  __fput+0x3b9/0xb70 fs/file_table.c:384
  task_work_run+0x14d/0x240 kernel/task_work.c:180
  exit_task_work include/linux/task_work.h:38 [inline]
  do_exit+0xa8a/0x2ad0 kernel/exit.c:871
  do_group_exit+0xd4/0x2a0 kernel/exit.c:1020
  __do_sys_exit_group kernel/exit.c:1031 [inline]
  __se_sys_exit_group kernel/exit.c:1029 [inline]
  __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1029
  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

The buggy address belongs to the object at ffff88802f4fc800
 which belongs to the cache sock_inode_cache of size 1408
The buggy address is located 128 bytes inside of
 freed 1408-byte region [ffff88802f4fc800, ffff88802f4fcd80)

The buggy address belongs to the physical page:
page:ffffea0000bd3e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f4f8
head:ffffea0000bd3e00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888013b06b40 0000000000000000 0000000000000001
raw: 0000000000000000 0000000080150015 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE), pid 4956, tgid 4956 (sshd), ts 31423924727, free_ts 0
  set_page_owner include/linux/page_owner.h:31 [inline]
  post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1533
  prep_new_page mm/page_alloc.c:1540 [inline]
  get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3311
  __alloc_pages+0x22f/0x2440 mm/page_alloc.c:4567
  __alloc_pages_node include/linux/gfp.h:238 [inline]
  alloc_pages_node include/linux/gfp.h:261 [inline]
  alloc_slab_page mm/slub.c:2190 [inline]
  allocate_slab mm/slub.c:2354 [inline]
  new_slab+0xcc/0x3a0 mm/slub.c:2407
  ___slab_alloc+0x4af/0x19a0 mm/slub.c:3540
  __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3625
  __slab_alloc_node mm/slub.c:3678 [inline]
  slab_alloc_node mm/slub.c:3850 [inline]
  kmem_cache_alloc_lru+0x379/0x6f0 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
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802f4fc780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802f4fc800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802f4fc880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88802f4fc900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f4fc980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

The Linux kernel CVE team has assigned CVE-2024-26625 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 4.19.307 with commit 6b950c712a9a
	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 5.4.269 with commit 64babb17e815
	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 5.10.210 with commit d0b5b1f12429
	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 5.15.149 with commit dbc1b89981f9
	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 6.1.77 with commit 9c333d9891f3
	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 6.6.16 with commit 3151051b787f
	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 6.7.4 with commit 8e51f084b571
	Issue introduced in 2.6.35 with commit 43815482370c and fixed in 6.8 with commit aa2b2eb39348

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-26625
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	net/llc/af_llc.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/6b950c712a9a05cdda4aea7fcb2848766576c11b
	https://git.kernel.org/stable/c/64babb17e8150771c58575d8f93a35c5296b499f
	https://git.kernel.org/stable/c/d0b5b1f12429df3cd9751ab8b2f53729b77733b7
	https://git.kernel.org/stable/c/dbc1b89981f9c5360277071d33d7f04a43ffda4a
	https://git.kernel.org/stable/c/9c333d9891f34cea8af1b229dc754552304c8eee
	https://git.kernel.org/stable/c/3151051b787f7cd7e3329ea0016eb9113c248812
	https://git.kernel.org/stable/c/8e51f084b5716653f19e291ed5f026791d4b3ed4
	https://git.kernel.org/stable/c/aa2b2eb3934859904c287bf5434647ba72e14c1c