Subject: CVE-2024-26815: net/sched: taprio: proper TCA_TAPRIO_TC_ENTRY_INDEX check

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

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

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

net/sched: taprio: proper TCA_TAPRIO_TC_ENTRY_INDEX check

taprio_parse_tc_entry() is not correctly checking
TCA_TAPRIO_TC_ENTRY_INDEX attribute:

	int tc; // Signed value

	tc = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_INDEX]);
	if (tc >= TC_QOPT_MAX_QUEUE) {
		NL_SET_ERR_MSG_MOD(extack, "TC entry index out of range");
		return -ERANGE;
	}

syzbot reported that it could fed arbitary negative values:

UBSAN: shift-out-of-bounds in net/sched/sch_taprio.c:1722:18
shift exponent -2147418108 is negative
CPU: 0 PID: 5066 Comm: syz-executor367 Not tainted 6.8.0-rc7-syzkaller-00136-gc8a5c731fd12 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
  ubsan_epilogue lib/ubsan.c:217 [inline]
  __ubsan_handle_shift_out_of_bounds+0x3c7/0x420 lib/ubsan.c:386
  taprio_parse_tc_entry net/sched/sch_taprio.c:1722 [inline]
  taprio_parse_tc_entries net/sched/sch_taprio.c:1768 [inline]
  taprio_change+0xb87/0x57d0 net/sched/sch_taprio.c:1877
  taprio_init+0x9da/0xc80 net/sched/sch_taprio.c:2134
  qdisc_create+0x9d4/0x1190 net/sched/sch_api.c:1355
  tc_modify_qdisc+0xa26/0x1e40 net/sched/sch_api.c:1776
  rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6617
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
  netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
  netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
  ___sys_sendmsg net/socket.c:2638 [inline]
  __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f1b2dea3759
Code: 48 83 c4 28 c3 e8 d7 19 00 00 0f 1f 80 00 00 00 00 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:00007ffd4de452f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1b2def0390 RCX: 00007f1b2dea3759
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 0000000000000003 R08: 0000555500000000 R09: 0000555500000000
R10: 0000555500000000 R11: 0000000000000246 R12: 00007ffd4de45340
R13: 00007ffd4de45310 R14: 0000000000000001 R15: 00007ffd4de45340

The Linux kernel CVE team has assigned CVE-2024-26815 to this issue.

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

	Issue introduced in 6.1 with commit a54fc09e4cba and fixed in 6.1.83 with commit bd2474a45df7
	Issue introduced in 6.1 with commit a54fc09e4cba and fixed in 6.6.23 with commit 6915b1b28fe5
	Issue introduced in 6.1 with commit a54fc09e4cba and fixed in 6.7.11 with commit 860e838fb089
	Issue introduced in 6.1 with commit a54fc09e4cba and fixed in 6.8.2 with commit 9b720bb1a69a
	Issue introduced in 6.1 with commit a54fc09e4cba and fixed in 6.9 with commit 343041b59b78

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-2024-26815
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/sched/sch_taprio.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/bd2474a45df7c11412c2587de3d4e43760531418
	https://git.kernel.org/stable/c/6915b1b28fe57e92c78e664366dc61c4f15ff03b
	https://git.kernel.org/stable/c/860e838fb089d652a446ced52cbdf051285b68e7
	https://git.kernel.org/stable/c/9b720bb1a69a9f12a4a5c86b6f89386fe05ed0f2
	https://git.kernel.org/stable/c/343041b59b7810f9cdca371f445dd43b35c740b1