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Eric Dumazet 40dddd4b8b ppp: fix ppp_async_encode() illegal access
syzbot reported an issue in ppp_async_encode() [1]

In this case, pppoe_sendmsg() is called with a zero size.
Then ppp_async_encode() is called with an empty skb.

BUG: KMSAN: uninit-value in ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline]
 BUG: KMSAN: uninit-value in ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675
  ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline]
  ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675
  ppp_async_send+0x130/0x1b0 drivers/net/ppp/ppp_async.c:634
  ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2280 [inline]
  ppp_input+0x1f1/0xe60 drivers/net/ppp/ppp_generic.c:2304
  pppoe_rcv_core+0x1d3/0x720 drivers/net/ppp/pppoe.c:379
  sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1113
  __release_sock+0x1da/0x330 net/core/sock.c:3072
  release_sock+0x6b/0x250 net/core/sock.c:3626
  pppoe_sendmsg+0x2b8/0xb90 drivers/net/ppp/pppoe.c:903
  sock_sendmsg_nosec net/socket.c:729 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:744
  ____sys_sendmsg+0x903/0xb60 net/socket.c:2602
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2656
  __sys_sendmmsg+0x3c1/0x960 net/socket.c:2742
  __do_sys_sendmmsg net/socket.c:2771 [inline]
  __se_sys_sendmmsg net/socket.c:2768 [inline]
  __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2768
  x64_sys_call+0xb6e/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:308
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
  slab_post_alloc_hook mm/slub.c:4092 [inline]
  slab_alloc_node mm/slub.c:4135 [inline]
  kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4187
  kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
  __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
  alloc_skb include/linux/skbuff.h:1322 [inline]
  sock_wmalloc+0xfe/0x1a0 net/core/sock.c:2732
  pppoe_sendmsg+0x3a7/0xb90 drivers/net/ppp/pppoe.c:867
  sock_sendmsg_nosec net/socket.c:729 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:744
  ____sys_sendmsg+0x903/0xb60 net/socket.c:2602
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2656
  __sys_sendmmsg+0x3c1/0x960 net/socket.c:2742
  __do_sys_sendmmsg net/socket.c:2771 [inline]
  __se_sys_sendmmsg net/socket.c:2768 [inline]
  __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2768
  x64_sys_call+0xb6e/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:308
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 5411 Comm: syz.1.14 Not tainted 6.12.0-rc1-syzkaller-00165-g360c1f1f24c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+1d121645899e7692f92a@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241009185802.3763282-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-10 08:47:13 -07:00
Documentation docs: netdev: document guidance on cleanup patches 2024-10-10 08:35:20 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
arch move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
block move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
drivers ppp: fix ppp_async_encode() illegal access 2024-10-10 08:47:13 -07:00
fs three small ksmbd server fixes 2024-10-03 09:38:16 -07:00
include mctp: Handle error of rtnl_register_module(). 2024-10-10 15:39:35 +02:00
init Rust changes for v6.12 2024-09-25 10:25:40 -07:00
io_uring for-6.12/io_uring-20240922 2024-09-24 11:11:38 -07:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel Getting rid of asm/unaligned.h includes 2024-10-02 16:42:28 -07:00
lib vfs-6.12-rc2.fixes.2 2024-10-03 09:22:50 -07:00
mm 19 hotfixes. 13 are cc:stable. 2024-09-27 10:27:22 -07:00
net phonet: Handle error of rtnl_register_module(). 2024-10-10 15:39:36 +02:00
rust Rust changes for v6.12 2024-09-25 10:25:40 -07:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts Reduce Coccinelle choices in string_choices.cocci 2024-09-28 21:33:11 +02:00
security move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
sound move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
tools selftests: netfilter: conntrack_vrf.sh: add fib test case 2024-10-09 23:31:15 +02:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt x86: 2024-09-28 09:20:14 -07:00
.clang-format clang-format: Update with v6.11-rc1's `for_each` macro list 2024-08-02 13:20:31 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap Summary 2024-09-24 11:08:40 -07:00
.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 MAINTAINERS: Mark powerpc spufs as orphaned 2024-08-19 21:27:56 +10:00
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 net: hns3/hns: Update the maintainer for the HNS3/HNS ethernet driver 2024-10-09 13:40:42 +01:00
Makefile Linux 6.12-rc1 2024-09-29 15:06:19 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 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.