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Ilya Shchipletsov a4fd163aed netrom: check buffer length before accessing it
Syzkaller reports an uninit value read from ax25cmp when sending raw message
through ieee802154 implementation.

=====================================================
BUG: KMSAN: uninit-value in ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119
 ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119
 nr_dev_get+0x20e/0x450 net/netrom/nr_route.c:601
 nr_route_frame+0x1a2/0xfc0 net/netrom/nr_route.c:774
 nr_xmit+0x5a/0x1c0 net/netrom/nr_dev.c:144
 __netdev_start_xmit include/linux/netdevice.h:4940 [inline]
 netdev_start_xmit include/linux/netdevice.h:4954 [inline]
 xmit_one net/core/dev.c:3548 [inline]
 dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564
 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349
 dev_queue_xmit include/linux/netdevice.h:3134 [inline]
 raw_sendmsg+0x654/0xc10 net/ieee802154/socket.c:299
 ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
 __sys_sendmsg net/socket.c:2667 [inline]
 __do_sys_sendmsg net/socket.c:2676 [inline]
 __se_sys_sendmsg net/socket.c:2674 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
 slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560
 __alloc_skb+0x318/0x740 net/core/skbuff.c:651
 alloc_skb include/linux/skbuff.h:1286 [inline]
 alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334
 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2780
 sock_alloc_send_skb include/net/sock.h:1884 [inline]
 raw_sendmsg+0x36d/0xc10 net/ieee802154/socket.c:282
 ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
 __sys_sendmsg net/socket.c:2667 [inline]
 __do_sys_sendmsg net/socket.c:2676 [inline]
 __se_sys_sendmsg net/socket.c:2674 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 0 PID: 5037 Comm: syz-executor166 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================

This issue occurs because the skb buffer is too small, and it's actual
allocation is aligned. This hides an actual issue, which is that nr_route_frame
does not validate the buffer size before using it.

Fix this issue by checking skb->len before accessing any fields in skb->data.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Co-developed-by: Nikita Marushkin <hfggklm@gmail.com>
Signed-off-by: Nikita Marushkin <hfggklm@gmail.com>
Signed-off-by: Ilya Shchipletsov <rabbelkin@mail.ru>
Link: https://patch.msgid.link/20241219082308.3942-1-rabbelkin@mail.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-23 10:04:55 -08:00
arch hyperv-fixes for v6.13-rc4 2024-12-18 09:55:55 -08:00
block block: Fix potential deadlock while freezing queue and acquiring sysfs_lock 2024-12-13 10:51:58 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: rsassa-pkcs1 - Copy source data for SG list 2024-12-10 13:34:05 +08:00
Documentation USB driver fixes for 6.13-rc3 2024-12-14 09:35:22 -08:00
drivers net: Fix netns for ip_tunnel_init_flow() 2024-12-23 10:04:41 -08:00
fs three kernel server fixes 2024-12-19 08:45:37 -08:00
include tracing fixes for v6.13: 2024-12-18 10:03:33 -08:00
init - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
io_uring io_uring/rsrc: don't put/free empty buffers 2024-12-12 08:01:52 -07:00
ipc - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
kernel tracing fixes for v6.13: 2024-12-18 10:03:33 -08:00
lib - Remove if_not_guard() as it is generating incorrect code 2024-12-09 10:34:41 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm slab fixes for 6.13-rc3 2024-12-13 09:43:50 -08:00
net netrom: check buffer length before accessing it 2024-12-23 10:04:55 -08:00
rust Including fixes from can and netfilter. 2024-12-19 09:19:11 -08:00
samples BPF fixes: 2024-12-06 15:07:48 -08:00
scripts A single fix for a docs-build regression caused by the EXPORT_SYMBOL_NS() 2024-12-13 09:46:02 -08:00
security selinux/stable-6.13 PR 20241217 2024-12-18 12:10:15 -08:00
sound soc: fixes for 6.13 2024-12-16 10:10:53 -08:00
tools selftests: drv-net: test empty queue and NAPI responses in netlink 2024-12-20 11:57:29 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt VFIO updates for v6.13 2024-11-27 12:57:03 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: enable Clippy's check-private-items 2024-10-07 21:39:57 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
.mailmap media updates for v6.13-rc1 2024-11-20 14:01:15 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS wireless fixes for v6.13-rc5 2024-12-19 18:53:15 -08:00
Makefile Linux 6.13-rc3 2024-12-15 15:58:23 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.