cve/published/2022/CVE-2022-49916.mbox

From bippy-1.1.0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@kernel.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2022-49916: rose: Fix NULL pointer dereference in rose_send_frame()

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

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

rose: Fix NULL pointer dereference in rose_send_frame()

The syzkaller reported an issue:

KASAN: null-ptr-deref in range [0x0000000000000380-0x0000000000000387]
CPU: 0 PID: 4069 Comm: kworker/0:15 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: rcu_gp srcu_invoke_callbacks
RIP: 0010:rose_send_frame+0x1dd/0x2f0 net/rose/rose_link.c:101
Call Trace:
 <IRQ>
 rose_transmit_clear_request+0x1d5/0x290 net/rose/rose_link.c:255
 rose_rx_call_request+0x4c0/0x1bc0 net/rose/af_rose.c:1009
 rose_loopback_timer+0x19e/0x590 net/rose/rose_loopback.c:111
 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x1d0/0x9c8 kernel/softirq.c:571
 [...]
 </IRQ>

It triggers NULL pointer dereference when 'neigh->dev->dev_addr' is
called in the rose_send_frame(). It's the first occurrence of the
`neigh` is in rose_loopback_timer() as `rose_loopback_neigh', and
the 'dev' in 'rose_loopback_neigh' is initialized sa nullptr.

It had been fixed by commit 3b3fd068c56e3fbea30090859216a368398e39bf
("rose: Fix Null pointer dereference in rose_send_frame()") ever.
But it's introduced by commit 3c53cd65dece47dd1f9d3a809f32e59d1d87b2b8
("rose: check NULL rose_loopback_neigh->loopback") again.

We fix it by add NULL check in rose_transmit_clear_request(). When
the 'dev' in 'neigh' is NULL, we don't reply the request and just
clear it.

syzkaller don't provide repro, and I provide a syz repro like:
r0 = syz_init_net_socket$bt_sco(0x1f, 0x5, 0x2)
ioctl$sock_inet_SIOCSIFFLAGS(r0, 0x8914, &(0x7f0000000180)={'rose0\x00', 0x201})
r1 = syz_init_net_socket$rose(0xb, 0x5, 0x0)
bind$rose(r1, &(0x7f00000000c0)=@full={0xb, @dev, @null, 0x0, [@null, @null, @netrom, @netrom, @default, @null]}, 0x40)
connect$rose(r1, &(0x7f0000000240)=@short={0xb, @dev={0xbb, 0xbb, 0xbb, 0x1, 0x0}, @remote={0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0x1}, 0x1, @netrom={0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0x0, 0x0}}, 0x1c)

The Linux kernel CVE team has assigned CVE-2022-49916 to this issue.


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

	Issue introduced in 4.9.327 with commit 76885373129b13df35ecc9b4ee86ea5840f12133 and fixed in 4.9.333 with commit 01b9c68c121847d05a4ccef68244dadf82bfa331
	Issue introduced in 4.14.292 with commit b8f9de195d6303f52bae16c7911f35ac14ba7e3d and fixed in 4.14.299 with commit bbc03d74e641e824754443b908454ca9e203773e
	Issue introduced in 4.19.257 with commit 0aae33feb7a56b28318f92c960a3d08d9c305984 and fixed in 4.19.265 with commit 5b46adfbee1e429f33b10a88d6c00fa88f3d6c77
	Issue introduced in 5.4.212 with commit 6e4b20d548fc97ecbdca15c8d96302ee5e3e6313 and fixed in 5.4.224 with commit b13be5e852b03f376058027e462fad4230240891
	Issue introduced in 5.10.140 with commit de3deadd11987070788b48825bec4647458b988d and fixed in 5.10.154 with commit f06186e5271b980bac03f5c97276ed0146ddc9b0
	Issue introduced in 5.15.64 with commit 9cf85759e104d7e9c3fd8920a554195b715d6797 and fixed in 5.15.78 with commit 3e2129c67daca21043a26575108f6286c85e71f6
	Issue introduced in 6.0 with commit 3c53cd65dece47dd1f9d3a809f32e59d1d87b2b8 and fixed in 6.0.8 with commit a601e5eded33bb88b8a42743db8fef3ad41dd97e
	Issue introduced in 6.0 with commit 3c53cd65dece47dd1f9d3a809f32e59d1d87b2b8 and fixed in 6.1 with commit e97c089d7a49f67027395ddf70bf327eeac2611e
	Issue introduced in 5.19.6 with commit 9197ca40fd9de265caedba70d0cb5814c4e45952

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-2022-49916
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/rose/rose_link.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/01b9c68c121847d05a4ccef68244dadf82bfa331
	https://git.kernel.org/stable/c/bbc03d74e641e824754443b908454ca9e203773e
	https://git.kernel.org/stable/c/5b46adfbee1e429f33b10a88d6c00fa88f3d6c77
	https://git.kernel.org/stable/c/b13be5e852b03f376058027e462fad4230240891
	https://git.kernel.org/stable/c/f06186e5271b980bac03f5c97276ed0146ddc9b0
	https://git.kernel.org/stable/c/3e2129c67daca21043a26575108f6286c85e71f6
	https://git.kernel.org/stable/c/a601e5eded33bb88b8a42743db8fef3ad41dd97e
	https://git.kernel.org/stable/c/e97c089d7a49f67027395ddf70bf327eeac2611e