dacab578c7
syzbot triggered the following splat [1], sending an empty message
through pppoe_sendmsg().
When VLAN_FLAG_REORDER_HDR flag is set, vlan_dev_hard_header()
does not push extra bytes for the VLAN header, because vlan is offloaded.
Unfortunately vlan_dev_hard_start_xmit() first reads veth->h_vlan_proto
before testing (vlan->flags & VLAN_FLAG_REORDER_HDR).
We need to swap the two conditions.
[1]
BUG: KMSAN: uninit-value in vlan_dev_hard_start_xmit+0x171/0x7f0 net/8021q/vlan_dev.c:111
vlan_dev_hard_start_xmit+0x171/0x7f0 net/8021q/vlan_dev.c:111
__netdev_start_xmit include/linux/netdevice.h:4883 [inline]
netdev_start_xmit include/linux/netdevice.h:4897 [inline]
xmit_one net/core/dev.c:3580 [inline]
dev_hard_start_xmit+0x253/0xa20 net/core/dev.c:3596
__dev_queue_xmit+0x3c7f/0x5ac0 net/core/dev.c:4246
dev_queue_xmit include/linux/netdevice.h:3053 [inline]
pppoe_sendmsg+0xa93/0xb80 drivers/net/ppp/pppoe.c:900
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0xa24/0xe40 net/socket.c:2501
___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555
__sys_sendmmsg+0x411/0xa50 net/socket.c:2641
__do_sys_sendmmsg net/socket.c:2670 [inline]
__se_sys_sendmmsg net/socket.c:2667 [inline]
__x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Uninit was created at:
slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774
slab_alloc_node mm/slub.c:3452 [inline]
kmem_cache_alloc_node+0x543/0xab0 mm/slub.c:3497
kmalloc_reserve+0x148/0x470 net/core/skbuff.c:520
__alloc_skb+0x3a7/0x850 net/core/skbuff.c:606
alloc_skb include/linux/skbuff.h:1277 [inline]
sock_wmalloc+0xfe/0x1a0 net/core/sock.c:2583
pppoe_sendmsg+0x3af/0xb80 drivers/net/ppp/pppoe.c:867
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0xa24/0xe40 net/socket.c:2501
___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555
__sys_sendmmsg+0x411/0xa50 net/socket.c:2641
__do_sys_sendmmsg net/socket.c:2670 [inline]
__se_sys_sendmmsg net/socket.c:2667 [inline]
__x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
CPU: 0 PID: 29770 Comm: syz-executor.0 Not tainted 6.3.0-rc6-syzkaller-gc478e5b17829 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Fixes:
|
||
---|---|---|
Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
io_uring | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
rust | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
.rustfmt.toml | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
README
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 Restructured Text 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.