ethtool - "vmalloc: allocation failure: 0 bytes" message

[Eric Desrochers]

If ->get_regs_len() callback return 0, we allocate 0 bytes of memory, what print the following warning in kern.log :

vmalloc: allocation failure: 0 bytes
ethtool: page allocation failure: order:0, mode:0x24080c2
CPU: 21 PID: 7668 Comm: ethtool Tainted: G 4.4.0-62-generic #83-Ubuntu
Hardware name:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0000000000000286 000000005949f325 ffff8801fddcfba8 ffffffff813f7c63
00000000024080c2 ffffffff81ccfe30 ffff8801fddcfc38 ffffffff8119498a
ffffffff81ccfe30 ffff8801fddcfbc8 0000000000000018 ffff8801fddcfc48
Call Trace:
[<ffffffff813f7c63>] dump_stack+0x63/0x90
[<ffffffff8119498a>] warn_alloc_failed+0xfa/0x150
[<ffffffff811d1082>] __vmalloc_node_range+0x202/0x290
[<ffffffff8183812e>] ? _raw_spin_unlock_bh+0x1e/0x20
[<ffffffff811d1214>] vzalloc+0x54/0x60
[<ffffffff81733c57>] ? dev_ethtool+0xfc7/0x1ef0
[<ffffffff81733c57>] dev_ethtool+0xfc7/0x1ef0
[<ffffffff81746362>] dev_ioctl+0x182/0x580
[<ffffffff8170d4a2>] sock_do_ioctl+0x42/0x50
[<ffffffff8170d9a2>] sock_ioctl+0x1d2/0x290
[<ffffffff812227af>] do_vfs_ioctl+0x29f/0x490
[<ffffffff8106b514>] ? __do_page_fault+0x1b4/0x400
[<ffffffff81222a19>] SyS_ioctl+0x79/0x90
[<ffffffff818385f2>] entry_SYSCALL_64_fastpath+0x16/0x71

break-fix: - 3808d34838184fd29088d6b3a364ba2f1c018fb6

[Eric Desrochers (slashd)]

An upstream fix is found upstream preventing the warning in ethtool code

* Reference :
https://patchwork.ozlabs.org/patch/722971/

* Commit :
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3808d34838184fd29088d6b3a364ba2f1c018fb6

--
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 236a21e..d92de0a 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1405,9 +1405,12 @@ static int ethtool_get_regs(struct net_device *dev, char __user *useraddr)
        if (regs.len > reglen)
                regs.len = reglen;

- regbuf = vzalloc(reglen);
- if (reglen && !regbuf)
- return -ENOMEM;
+ regbuf = NULL;
+ if (reglen) {
+ regbuf = vzalloc(reglen);
+ if (!regbuf)
+ return -ENOMEM;
+ }

        ops->get_regs(dev, &regs, regbuf);
--

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1703944

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Eric Desrochers (slashd)]

PATCH submitted to Ubuntu kernel-team for approval.

[Eric Desrochers (slashd)]

This is the patch I have sent to kernel-team ML.

[Kleber Sacilotto de Souza (kleber-souza)]

Patch was already applied as part of Xenial update to 4.4.73 stable release (LP #1698817).

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]