Subject: CVE-2024-36915: nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies

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

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

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

nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies

syzbot reported unsafe calls to copy_from_sockptr() [1]

Use copy_safe_from_sockptr() instead.

[1]

BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
 BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline]
 BUG: KASAN: slab-out-of-bounds in nfc_llcp_setsockopt+0x6c2/0x850 net/nfc/llcp_sock.c:255
Read of size 4 at addr ffff88801caa1ec3 by task syz-executor459/5078

CPU: 0 PID: 5078 Comm: syz-executor459 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
  print_address_description mm/kasan/report.c:377 [inline]
  print_report+0x169/0x550 mm/kasan/report.c:488
  kasan_report+0x143/0x180 mm/kasan/report.c:601
  copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
  copy_from_sockptr include/linux/sockptr.h:55 [inline]
  nfc_llcp_setsockopt+0x6c2/0x850 net/nfc/llcp_sock.c:255
  do_sock_setsockopt+0x3b1/0x720 net/socket.c:2311
  __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
  __do_sys_setsockopt net/socket.c:2343 [inline]
  __se_sys_setsockopt net/socket.c:2340 [inline]
  __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xfd/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f7fac07fd89
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff660eb788 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f7fac07fd89
RDX: 0000000000000000 RSI: 0000000000000118 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000020000a80 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

The Linux kernel CVE team has assigned CVE-2024-36915 to this issue.

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

	Fixed in 6.6.47 with commit 0f1061332030
	Fixed in 6.8.10 with commit 29dc0ea979d4
	Fixed in 6.9 with commit 7a87441c9651

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-2024-36915
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/nfc/llcp_sock.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/0f106133203021533cb753e80d75896f4ad222f8
	https://git.kernel.org/stable/c/29dc0ea979d433dd3c26abc8fa971550bdc05107
	https://git.kernel.org/stable/c/7a87441c9651ba37842f4809224aca13a554a26f