From: Simon Horman <simon.horman@corigine.com>
To: Pedro Tammela <pctammela@mojatatu.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, kuniyu@amazon.com,
dh.herrmann@gmail.com, jhs@mojatatu.com
Subject: Re: [PATCH net] net/netlink: fix NETLINK_LIST_MEMBERSHIPS group array length check
Date: Fri, 26 May 2023 11:26:41 +0200 [thread overview]
Message-ID: <ZHB7UezB3+NcYn10@corigine.com> (raw)
In-Reply-To: <20230525144609.503744-1-pctammela@mojatatu.com>
On Thu, May 25, 2023 at 11:46:09AM -0300, Pedro Tammela wrote:
> For the socket option 'NETLINK_LIST_MEMBERSHIPS' the length is defined
> as the number of u32 required to represent the whole bitset.
> User space then usually queries the required size and issues a subsequent
> getsockopt call with the correct parameters[1].
>
> The current code has an unit mismatch between 'len' and 'pos', where
> 'len' is the number of u32 in the passed array while 'pos' is the
> number of bytes iterated in the groups bitset.
> For netlink groups greater than 32, which from a quick glance
> is a rare occasion, the mismatch causes the misreport of groups e.g.
> if a rtnl socket is a member of group 34, it's reported as not a member
> (all 0s).
>
> [1] https://github.com/systemd/systemd/blob/9c9b9b89151c3e29f3665e306733957ee3979853/src/libsystemd/sd-netlink/netlink-socket.c#L26
>
> Fixes: b42be38b2778 ("netlink: add API to retrieve all group memberships")
> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
next prev parent reply other threads:[~2023-05-26 9:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-25 14:46 [PATCH net] net/netlink: fix NETLINK_LIST_MEMBERSHIPS group array length check Pedro Tammela
2023-05-26 9:26 ` Simon Horman [this message]
2023-05-27 3:33 ` Jakub Kicinski
2023-05-27 15:01 ` Pedro Tammela
2023-05-29 6:40 ` Jakub Kicinski
2023-05-29 14:37 ` Pedro Tammela
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZHB7UezB3+NcYn10@corigine.com \
--to=simon.horman@corigine.com \
--cc=davem@davemloft.net \
--cc=dh.herrmann@gmail.com \
--cc=edumazet@google.com \
--cc=jhs@mojatatu.com \
--cc=kuba@kernel.org \
--cc=kuniyu@amazon.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=pctammela@mojatatu.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).