Linux kernel source tree
Go to file
Paolo Abeni c26c192c3d udp: properly deal with xfrm encap and ADDRFORM
UDP GRO accounting assumes that the GRO receive callback is always
set when the UDP tunnel is enabled, but syzkaller proved otherwise,
leading tot the following splat:

WARNING: CPU: 0 PID: 5837 at net/ipv4/udp_offload.c:123 udp_tunnel_update_gro_rcv+0x28d/0x4c0 net/ipv4/udp_offload.c:123
Modules linked in:
CPU: 0 UID: 0 PID: 5837 Comm: syz-executor850 Not tainted 6.14.0-syzkaller-13320-g420aabef3ab5 #0 PREEMPT(full)
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:udp_tunnel_update_gro_rcv+0x28d/0x4c0 net/ipv4/udp_offload.c:123
Code: 00 00 e8 c6 5a 2f f7 48 c1 e5 04 48 8d b5 20 53 c7 9a ba 10
      00 00 00 4c 89 ff e8 ce 87 99 f7 e9 ce 00 00 00 e8 a4 5a 2f
      f7 90 <0f> 0b 90 e9 de fd ff ff bf 01 00 00 00 89 ee e8 cf
      5e 2f f7 85 ed
RSP: 0018:ffffc90003effa88 EFLAGS: 00010293
RAX: ffffffff8a93fc9c RBX: 0000000000000000 RCX: ffff8880306f9e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8a93fabe R09: 1ffffffff20bfb2e
R10: dffffc0000000000 R11: fffffbfff20bfb2f R12: ffff88814ef21738
R13: dffffc0000000000 R14: ffff88814ef21778 R15: 1ffff11029de42ef
FS:  0000000000000000(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f04eec760d0 CR3: 000000000eb38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 udp_tunnel_cleanup_gro include/net/udp_tunnel.h:205 [inline]
 udpv6_destroy_sock+0x212/0x270 net/ipv6/udp.c:1829
 sk_common_release+0x71/0x2e0 net/core/sock.c:3896
 inet_release+0x17d/0x200 net/ipv4/af_inet.c:435
 __sock_release net/socket.c:647 [inline]
 sock_close+0xbc/0x240 net/socket.c:1391
 __fput+0x3e9/0x9f0 fs/file_table.c:465
 task_work_run+0x251/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa11/0x27f0 kernel/exit.c:953
 do_group_exit+0x207/0x2c0 kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f04eebfac79
Code: Unable to access opcode bytes at 0x7f04eebfac4f.
RSP: 002b:00007fffdcaa34a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f04eebfac79
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f04eec75270 R08: ffffffffffffffb8 R09: 00007fffdcaa36c8
R10: 0000200000000000 R11: 0000000000000246 R12: 00007f04eec75270
R13: 0000000000000000 R14: 00007f04eec75cc0 R15: 00007f04eebcca70

Address the issue moving the accounting hook into
setup_udp_tunnel_sock() and set_xfrm_gro_udp_encap_rcv(), where
the GRO callback is actually set.

set_xfrm_gro_udp_encap_rcv() is prone to races with IPV6_ADDRFORM,
run the relevant setsockopt under the socket lock to ensure using
consistent values of sk_family and up->encap_type.

Refactor the GRO callback selection code, to make it clear that
the function pointer is always initialized.

Reported-by: syzbot+8c469a2260132cd095c1@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8c469a2260132cd095c1
Fixes: 172bf009c1 ("xfrm: Support GRO for IPv4 ESP in UDP encapsulation")
Fixes: 5d7f5b2f6b ("udp_tunnel: use static call for GRO hooks when possible")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/92bcdb6899145a9a387c8fa9e3ca656642a43634.1744228733.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14 14:29:01 -07:00
arch net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
block treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes reverts the multibuffer hash testing as it is buggy. 2025-04-02 09:14:59 -07:00
Documentation net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
drivers net: phy: mediatek: add Airoha PHY ID to SoC driver 2025-04-11 20:18:31 -07:00
fs CRC cleanups for 6.15 2025-04-08 12:09:28 -07:00
include udp: properly deal with xfrm encap and ADDRFORM 2025-04-14 14:29:01 -07:00
init Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
io_uring io_uring/kbuf: reject zero sized provided buffers 2025-04-07 07:51:23 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel trace: tcp: Add tracepoint for tcp_sendmsg_locked() 2025-04-10 18:34:05 -07:00
lib CRC cleanups for 6.15 2025-04-08 12:09:28 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm Disable SLUB_TINY for build testing 2025-04-06 10:00:04 -07:00
net udp: properly deal with xfrm encap and ADDRFORM 2025-04-14 14:29:01 -07:00
rust Kbuild updates for v6.15 2025-04-05 15:46:50 -07:00
samples net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
scripts net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
security net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
sound soundwire fix for 6.15-rc1 2025-04-06 12:04:53 -07:00
tools selftest: net: Remove DCCP bits. 2025-04-11 18:58:10 -07:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-04-08 13:47:55 -07:00
.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: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.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: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00
.mailmap mailmap: add an entry for Nicolas Schier 2025-04-01 15:20:45 -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 Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
Makefile kbuild: Add '-fno-builtin-wcslen' 2025-04-08 12:03:26 -07:00
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.