A mirror of the official Linux kernel repository just in case
Go to file
Danielle Ratson a975d7d8a3 ethtool: Remove link_mode param and derive link params from driver
Some drivers clear the 'ethtool_link_ksettings' struct in their
get_link_ksettings() callback, before populating it with actual values.
Such drivers will set the new 'link_mode' field to zero, resulting in
user space receiving wrong link mode information given that zero is a
valid value for the field.

Another problem is that some drivers (notably tun) can report random
values in the 'link_mode' field. This can result in a general protection
fault when the field is used as an index to the 'link_mode_params' array
[1].

This happens because such drivers implement their set_link_ksettings()
callback by simply overwriting their private copy of
'ethtool_link_ksettings' struct with the one they get from the stack,
which is not always properly initialized.

Fix these problems by removing 'link_mode' from 'ethtool_link_ksettings'
and instead have drivers call ethtool_params_from_link_mode() with the
current link mode. The function will derive the link parameters (e.g.,
speed) from the link mode and fill them in the 'ethtool_link_ksettings'
struct.

v3:
	* Remove link_mode parameter and derive the link parameters in
	  the driver instead of passing link_mode parameter to ethtool
	  and derive it there.

v2:
	* Introduce 'cap_link_mode_supported' instead of adding a
	  validity field to 'ethtool_link_ksettings' struct.

[1]
general protection fault, probably for non-canonical address 0xdffffc00f14cc32c: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x000000078a661960-0x000000078a661967]
CPU: 0 PID: 8452 Comm: syz-executor360 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__ethtool_get_link_ksettings+0x1a3/0x3a0 net/ethtool/ioctl.c:446
Code: b7 3e fa 83 fd ff 0f 84 30 01 00 00 e8 16 b0 3e fa 48 8d 3c ed 60 d5 69 8a 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03
+38 d0 7c 08 84 d2 0f 85 b9
RSP: 0018:ffffc900019df7a0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888026136008 RCX: 0000000000000000
RDX: 00000000f14cc32c RSI: ffffffff873439ca RDI: 000000078a661960
RBP: 00000000ffff8880 R08: 00000000ffffffff R09: ffff88802613606f
R10: ffffffff873439bc R11: 0000000000000000 R12: 0000000000000000
R13: ffff88802613606c R14: ffff888011d0c210 R15: ffff888011d0c210
FS:  0000000000749300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004b60f0 CR3: 00000000185c2000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 linkinfo_prepare_data+0xfd/0x280 net/ethtool/linkinfo.c:37
 ethnl_default_notify+0x1dc/0x630 net/ethtool/netlink.c:586
 ethtool_notify+0xbd/0x1f0 net/ethtool/netlink.c:656
 ethtool_set_link_ksettings+0x277/0x330 net/ethtool/ioctl.c:620
 dev_ethtool+0x2b35/0x45d0 net/ethtool/ioctl.c:2842
 dev_ioctl+0x463/0xb70 net/core/dev_ioctl.c:440
 sock_do_ioctl+0x148/0x2d0 net/socket.c:1060
 sock_ioctl+0x477/0x6a0 net/socket.c:1177
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: c8907043c6 ("ethtool: Get link mode in use instead of speed and duplex parameters")
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-07 14:53:04 -07:00
arch Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
block block: Discard page cache of zone reset target range 2021-03-11 11:49:25 -07:00
certs certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID 2021-01-21 16:16:10 +00:00
crypto crypto: mips/poly1305 - enable for all MIPS processors 2021-03-08 11:52:17 +01:00
Documentation docs: ethtool: fix some copy-paste errors 2021-04-06 16:55:41 -07:00
drivers ethtool: Remove link_mode param and derive link params from driver 2021-04-07 14:53:04 -07:00
fs Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
include ethtool: Remove link_mode param and derive link params from driver 2021-04-07 14:53:04 -07:00
init Merge branch 'akpm' (patches from Andrew) 2021-03-14 12:23:34 -07:00
ipc fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
kernel bpf: program: Refuse non-O_RDWR flags in BPF_OBJ_GET 2021-04-01 14:33:48 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-24 18:16:04 -07:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
net ethtool: Remove link_mode param and derive link params from driver 2021-04-07 14:53:04 -07:00
samples Merge git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2021-03-09 17:15:56 -08:00
scripts kbuild: fix ld-version.sh to not be affected by locale 2021-03-13 11:12:13 +09:00
security selinux/stable-5.12 PR 20210322 2021-03-22 11:34:31 -07:00
sound sound fixes for 5.12-rc4 2021-03-19 09:53:32 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2021-04-02 11:00:46 -07:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt KVM: x86/mmu: Consider the hva in mmu_notifier retry 2021-02-22 13:16:53 -05:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
.mailmap Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
COPYING
CREDITS treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
Kbuild
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Add entry for Qualcomm IPC Router (QRTR) driver 2021-03-29 13:38:33 -07:00
Makefile Linux 5.12-rc4 2021-03-21 14:56:43 -07:00
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 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.