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Eric Dumazet 350a6640fa ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()
[ Upstream commit 8d975c15c0 ]

syzbot found __ip6_tnl_rcv() could access unitiliazed data [1].

Call pskb_inet_may_pull() to fix this, and initialize ipv6h
variable after this call as it can change skb->head.

[1]
 BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
 BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
 BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321
  __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
  INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
  IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321
  ip6ip6_dscp_ecn_decapsulate+0x178/0x1b0 net/ipv6/ip6_tunnel.c:727
  __ip6_tnl_rcv+0xd4e/0x1590 net/ipv6/ip6_tunnel.c:845
  ip6_tnl_rcv+0xce/0x100 net/ipv6/ip6_tunnel.c:888
 gre_rcv+0x143f/0x1870
  ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438
  ip6_input_finish net/ipv6/ip6_input.c:483 [inline]
  NF_HOOK include/linux/netfilter.h:314 [inline]
  ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492
  ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586
  dst_input include/net/dst.h:461 [inline]
  ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79
  NF_HOOK include/linux/netfilter.h:314 [inline]
  ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310
  __netif_receive_skb_one_core net/core/dev.c:5532 [inline]
  __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5646
  netif_receive_skb_internal net/core/dev.c:5732 [inline]
  netif_receive_skb+0x58/0x660 net/core/dev.c:5791
  tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
  tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002
  tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
  call_write_iter include/linux/fs.h:2084 [inline]
  new_sync_write fs/read_write.c:497 [inline]
  vfs_write+0x786/0x1200 fs/read_write.c:590
  ksys_write+0x20f/0x4c0 fs/read_write.c:643
  __do_sys_write fs/read_write.c:655 [inline]
  __se_sys_write fs/read_write.c:652 [inline]
  __x64_sys_write+0x93/0xd0 fs/read_write.c:652
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0x6d/0x140 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:2787
  tun_alloc_skb drivers/net/tun.c:1531 [inline]
  tun_get_user+0x1e8a/0x66d0 drivers/net/tun.c:1846
  tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
  call_write_iter include/linux/fs.h:2084 [inline]
  new_sync_write fs/read_write.c:497 [inline]
  vfs_write+0x786/0x1200 fs/read_write.c:590
  ksys_write+0x20f/0x4c0 fs/read_write.c:643
  __do_sys_write fs/read_write.c:655 [inline]
  __se_sys_write fs/read_write.c:652 [inline]
  __x64_sys_write+0x93/0xd0 fs/read_write.c:652
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 0 PID: 5034 Comm: syz-executor331 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023

Fixes: 0d3c703a9d ("ipv6: Cleanup IPv6 tunnel receive path")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240125170557.2663942-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:14:35 +00:00
arch riscv: Fix build error on rv32 + XIP 2024-02-05 20:14:34 +00:00
block blk-mq: fix IO hang from sbitmap wakeup race 2024-02-05 20:14:33 +00:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: api - Disallow identical driver names 2024-01-31 16:18:49 -08:00
Documentation ASoC: doc: Fix undefined SND_SOC_DAPM_NOPM argument 2024-02-05 20:14:26 +00:00
drivers net: phy: mediatek-ge-soc: sync driver with MediaTek SDK 2024-02-05 20:14:35 +00:00
fs ceph: fix invalid pointer access if get_quota_realm return ERR_PTR 2024-02-05 20:14:33 +00:00
include drm: using mul_u32_u32() requires linux/math64.h 2024-02-05 20:14:34 +00:00
init rootfs: Fix support for rootfstype= when root= is given 2024-01-25 15:35:46 -08:00
io_uring io_uring: adjust defer tw counting 2024-01-25 15:36:00 -08:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel perf: Fix the nr_addr_filters fix 2024-02-05 20:14:33 +00:00
lib kunit: run test suites only after module initialization completes 2024-02-05 20:14:34 +00:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memblock: fix crash when reserved memory is not added to memory 2024-01-31 16:19:12 -08:00
net ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv() 2024-02-05 20:14:35 +00:00
rust rust: Ignore preserve-most functions 2024-01-25 15:35:41 -08:00
samples vfio/mtty: Overhaul mtty interrupt handling 2024-01-10 17:16:55 +01:00
scripts scripts/get_abi: fix source path leak 2024-01-31 16:18:55 -08:00
security lsm: new security_file_ioctl_compat() hook 2024-01-31 16:18:54 -08:00
sound ALSA: hda/conexant: Fix headset auto detect fail in cx8070 and SN6140 2024-02-05 20:14:30 +00:00
tools selftests: net: give more time for GRO aggregation 2024-02-05 20:14:35 +00:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS Char/Misc driver fixes for 6.6-final 2023-10-28 07:51:27 -10:00
Makefile Linux 6.6.15 2024-01-31 16:19:14 -08:00
README

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

There are several guides for kernel developers and users. These guides can
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    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
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the problems which may result by upgrading your kernel.