4.9 LTS inclusion request for "net: fix nla_strcmp to handle more then one trailing null character"

4.9 LTS inclusion request for "net: fix nla_strcmp to handle more then one trailing null character"

[Maciej Żenczykowski]

Please pull into 4.9 LTS:

https://gitlab.arm.com/linux-arm/linux-power/-/commit/2c16db6c92b0ee4aa61e88366df82169e83c3f7e
"net: fix nla_strcmp to handle more then one trailing null character"

+++ lib/nlattr.c
@@ -379,7 +379,7 @@ int nla_strcmp(const struct nlattr *nla, const char *str)
-       if (attrlen > 0 && buf[attrlen - 1] == '\0')
+       while (attrlen > 0 && buf[attrlen - 1] == '\0')

which appears to be present in 4.14.233 (and presumably newer LTS),
but not in 4.9:

$ git log --oneline -n1
remotes/linux-stable/v4.14.233..143722a05028ebb8691d349007f85656a4e90a8e

We've got some code that is confirmed failing due to the lack of this one-liner,
and the fix is obvious enough...

(assuming it applies it presumably wouldn't hurt in 4.4 LTS either,
but I think that tree isn't even maintained, and I don't care about it
there)

Thanks,

Maciej Żenczykowski, Kernel Networking Developer @ Google

Re: 4.9 LTS inclusion request for "net: fix nla_strcmp to handle more then one trailing null character"

[Sasha Levin]

On Fri, Jun 10, 2022 at 05:50:55AM -0700, Maciej Żenczykowski wrote:
>Please pull into 4.9 LTS:
>
>https://gitlab.arm.com/linux-arm/linux-power/-/commit/2c16db6c92b0ee4aa61e88366df82169e83c3f7e
>"net: fix nla_strcmp to handle more then one trailing null character"
>
>+++ lib/nlattr.c
>@@ -379,7 +379,7 @@ int nla_strcmp(const struct nlattr *nla, const char *str)
>-       if (attrlen > 0 && buf[attrlen - 1] == '\0')
>+       while (attrlen > 0 && buf[attrlen - 1] == '\0')
>
>which appears to be present in 4.14.233 (and presumably newer LTS),
>but not in 4.9:
>
>$ git log --oneline -n1
>remotes/linux-stable/v4.14.233..143722a05028ebb8691d349007f85656a4e90a8e
>
>We've got some code that is confirmed failing due to the lack of this one-liner,
>and the fix is obvious enough...

Queued up, thanks!

>(assuming it applies it presumably wouldn't hurt in 4.4 LTS either,
>but I think that tree isn't even maintained, and I don't care about it
>there)

No, no one cares :)

-- 
Thanks,
Sasha