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Eric Dumazet 59c51c3b54 tunnels: do not assume mac header is set in skb_tunnel_check_pmtu()
commit 853a761488 upstream.

Recently added debug in commit f9aefd6b2a ("net: warn if mac header
was not set") caught a bug in skb_tunnel_check_pmtu(), as shown
in this syzbot report [1].

In ndo_start_xmit() paths, there is really no need to use skb->mac_header,
because skb->data is supposed to point at it.

[1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline]
WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413
Modules linked in:
CPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline]
RIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413
Code: 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 80 3c 02 00 0f 84 b9 fe ff ff 4c 89 ff e8 7c 0f d7 f9 e9 ac fe ff ff e8 c2 13 8a f9 <0f> 0b e9 28 fc ff ff e8 b6 13 8a f9 48 8b 54 24 70 48 b8 00 00 00
RSP: 0018:ffffc90002e4f520 EFLAGS: 00010212
RAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000
RDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003
RBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff
R10: 000000000000ffff R11: 0000000000000000 R12: 000000000000ffff
R13: 0000000000000000 R14: 000000000000ffcd R15: 000000000000001f
FS: 00007f3babba9700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 0000000075319000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
geneve_xmit_skb drivers/net/geneve.c:927 [inline]
geneve_xmit+0xcf8/0x35d0 drivers/net/geneve.c:1107
__netdev_start_xmit include/linux/netdevice.h:4805 [inline]
netdev_start_xmit include/linux/netdevice.h:4819 [inline]
__dev_direct_xmit+0x500/0x730 net/core/dev.c:4309
dev_direct_xmit include/linux/netdevice.h:3007 [inline]
packet_direct_xmit+0x1b8/0x2c0 net/packet/af_packet.c:282
packet_snd net/packet/af_packet.c:3073 [inline]
packet_sendmsg+0x21f4/0x55d0 net/packet/af_packet.c:3104
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2489
___sys_sendmsg+0xf3/0x170 net/socket.c:2543
__sys_sendmsg net/socket.c:2572 [inline]
__do_sys_sendmsg net/socket.c:2581 [inline]
__se_sys_sendmsg net/socket.c:2579 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2579
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f3baaa89109
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3babba9168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3baab9bf60 RCX: 00007f3baaa89109
RDX: 0000000000000000 RSI: 0000000020000a00 RDI: 0000000000000003
RBP: 00007f3baaae305d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe74f2543f R14: 00007f3babba9300 R15: 0000000000022000
</TASK>

Fixes: 4cb47a8644 ("tunnels: PMTU discovery support for directly bridged IP packets")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-07 17:52:19 +02:00
arch s390: remove unneeded 'select BUILD_BIN2C' 2022-07-07 17:52:18 +02:00
block block: Fix handling of offline queues in blk_mq_alloc_request_hctx() 2022-06-22 14:13:17 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:13:17 +02:00
crypto crypto: memneq - move into lib/ 2022-06-22 14:13:18 +02:00
Documentation iio: adc: vf610: fix conversion mode sysfs node name 2022-06-29 08:59:50 +02:00
drivers epic100: fix use after free on rmmod 2022-07-07 17:52:19 +02:00
fs io_uring: ensure that send/sendmsg and recv/recvmsg check sqe->ioprio 2022-07-07 17:52:19 +02:00
include linux/dim: Fix divide by 0 in RDMA DIM 2022-07-07 17:52:17 +02:00
init Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug 2022-06-09 10:21:25 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-09 10:21:17 +02:00
kernel tick/nohz: unexport __init-annotated tick_nohz_full_setup() 2022-07-02 16:39:23 +02:00
lib crypto: memneq - move into lib/ 2022-06-22 14:13:18 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm hugetlb: fix huge_pmd_unshare address update 2022-06-09 10:21:27 +02:00
net tunnels: do not assume mac header is set in skb_tunnel_check_pmtu() 2022-07-07 17:52:19 +02:00
samples samples/bpf, xdpsock: Fix race when running for fix duration of time 2022-04-08 14:40:21 +02:00
scripts modpost: fix section mismatch check for exported init/exit sections 2022-06-29 08:59:54 +02:00
security ima: remove the IMA_TEMPLATE Kconfig option 2022-06-09 10:21:25 +02:00
sound ALSA: hda/realtek: Add quirk for Clevo NS50PU 2022-06-29 08:59:45 +02:00
tools selftests/net: pass ipv6_args to udpgso_bench's IPv6 TCP test 2022-07-07 17:52:16 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: Prevent module exit until all VMs are freed 2022-04-08 14:40:38 +02:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add Amir as xfs maintainer for 5.10.y 2022-07-02 16:39:22 +02:00
Makefile Linux 5.10.128 2022-07-02 16:39:25 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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 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.