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Paolo Abeni c329b261af net: prevent skb corruption on frag list segmentation
Ian reported several skb corruptions triggered by rx-gro-list,
collecting different oops alike:

[   62.624003] BUG: kernel NULL pointer dereference, address: 00000000000000c0
[   62.631083] #PF: supervisor read access in kernel mode
[   62.636312] #PF: error_code(0x0000) - not-present page
[   62.641541] PGD 0 P4D 0
[   62.644174] Oops: 0000 [#1] PREEMPT SMP NOPTI
[   62.648629] CPU: 1 PID: 913 Comm: napi/eno2-79 Not tainted 6.4.0 #364
[   62.655162] Hardware name: Supermicro Super Server/A2SDi-12C-HLN4F, BIOS 1.7a 10/13/2022
[   62.663344] RIP: 0010:__udp_gso_segment (./include/linux/skbuff.h:2858
./include/linux/udp.h:23 net/ipv4/udp_offload.c:228 net/ipv4/udp_offload.c:261
net/ipv4/udp_offload.c:277)
[   62.687193] RSP: 0018:ffffbd3a83b4f868 EFLAGS: 00010246
[   62.692515] RAX: 00000000000000ce RBX: 0000000000000000 RCX: 0000000000000000
[   62.699743] RDX: ffffa124def8a000 RSI: 0000000000000079 RDI: ffffa125952a14d4
[   62.706970] RBP: ffffa124def8a000 R08: 0000000000000022 R09: 00002000001558c9
[   62.714199] R10: 0000000000000000 R11: 00000000be554639 R12: 00000000000000e2
[   62.721426] R13: ffffa125952a1400 R14: ffffa125952a1400 R15: 00002000001558c9
[   62.728654] FS:  0000000000000000(0000) GS:ffffa127efa40000(0000)
knlGS:0000000000000000
[   62.736852] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   62.742702] CR2: 00000000000000c0 CR3: 00000001034b0000 CR4: 00000000003526e0
[   62.749948] Call Trace:
[   62.752498]  <TASK>
[   62.779267] inet_gso_segment (net/ipv4/af_inet.c:1398)
[   62.787605] skb_mac_gso_segment (net/core/gro.c:141)
[   62.791906] __skb_gso_segment (net/core/dev.c:3403 (discriminator 2))
[   62.800492] validate_xmit_skb (./include/linux/netdevice.h:4862
net/core/dev.c:3659)
[   62.804695] validate_xmit_skb_list (net/core/dev.c:3710)
[   62.809158] sch_direct_xmit (net/sched/sch_generic.c:330)
[   62.813198] __dev_queue_xmit (net/core/dev.c:3805 net/core/dev.c:4210)
net/netfilter/core.c:626)
[   62.821093] br_dev_queue_push_xmit (net/bridge/br_forward.c:55)
[   62.825652] maybe_deliver (net/bridge/br_forward.c:193)
[   62.829420] br_flood (net/bridge/br_forward.c:233)
[   62.832758] br_handle_frame_finish (net/bridge/br_input.c:215)
[   62.837403] br_handle_frame (net/bridge/br_input.c:298
net/bridge/br_input.c:416)
[   62.851417] __netif_receive_skb_core.constprop.0 (net/core/dev.c:5387)
[   62.866114] __netif_receive_skb_list_core (net/core/dev.c:5570)
[   62.871367] netif_receive_skb_list_internal (net/core/dev.c:5638
net/core/dev.c:5727)
[   62.876795] napi_complete_done (./include/linux/list.h:37
./include/net/gro.h:434 ./include/net/gro.h:429 net/core/dev.c:6067)
[   62.881004] ixgbe_poll (drivers/net/ethernet/intel/ixgbe/ixgbe_main.c:3191)
[   62.893534] __napi_poll (net/core/dev.c:6498)
[   62.897133] napi_threaded_poll (./include/linux/netpoll.h:89
net/core/dev.c:6640)
[   62.905276] kthread (kernel/kthread.c:379)
[   62.913435] ret_from_fork (arch/x86/entry/entry_64.S:314)
[   62.917119]  </TASK>

In the critical scenario, rx-gro-list GRO-ed packets are fed, via a
bridge, both to the local input path and to an egress device (tun).

The segmentation of such packets unsafely writes to the cloned skbs
with shared heads.

This change addresses the issue by uncloning as needed the
to-be-segmented skbs.

Reported-by: Ian Kumlien <ian.kumlien@gmail.com>
Tested-by: Ian Kumlien <ian.kumlien@gmail.com>
Fixes: 3a1296a38d ("net: Support GRO/GSO fraglist chaining.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-08 10:03:26 +01:00
arch parisc architecture fixes and updates for kernel v6.5-rc1 (pt 2): 2023-07-05 10:28:38 -07:00
block block-6.5-2023-07-03 2023-07-03 18:48:38 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto This update includes the following changes: 2023-06-30 21:27:13 -07:00
Documentation Including fixes from bluetooth, bpf and wireguard. 2023-07-05 15:44:45 -07:00
drivers net: bgmac: postpone turning IRQs off to avoid SoC hangs 2023-07-08 10:02:15 +01:00
fs f2fs update for 6.5-rc1 2023-07-05 14:14:37 -07:00
include net: dsa: felix: make vsc9959_tas_guard_bands_update() visible to ocelot->ops 2023-07-06 19:10:22 -07:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring-6.5-2023-07-03 2023-07-03 18:43:10 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Including fixes from bluetooth, bpf and wireguard. 2023-07-05 15:44:45 -07:00
lib Char/Misc and other driver subsystem updates for 6.5-rc1 2023-07-03 12:46:47 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm gup: make the stack expansion warning a bit more targeted 2023-07-05 09:33:31 -07:00
net net: prevent skb corruption on frag list segmentation 2023-07-08 10:03:26 +01:00
rust rust: error: impl Debug for Error with errname() integration 2023-06-13 01:24:42 +02:00
samples Including fixes from bluetooth, bpf and wireguard. 2023-07-05 15:44:45 -07:00
scripts parisc architecture fixes and updates for kernel v6.5-rc1 (pt 2): 2023-07-05 10:28:38 -07:00
security Scope-based Resource Management infrastructure 2023-07-04 13:50:38 -07:00
sound soundwire updates for 6.5 2023-07-05 10:54:43 -07:00
tools Including fixes from bluetooth, bpf and wireguard. 2023-07-05 15:44:45 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM64: 2023-07-03 15:32:22 -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 Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap - New Drivers 2023-07-03 10:55:04 -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 - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
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 pwm: Changes for v6.5-rc1 2023-07-05 12:55:06 -07:00
Makefile Scope-based Resource Management infrastructure 2023-07-04 13:50:38 -07:00
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.