From: David Laight <David.Laight@aculab.com>
To: "'He Zhe'" <zhe.he@windriver.com>,
"paul@paul-moore.com" <paul@paul-moore.com>,
"eparis@redhat.com" <eparis@redhat.com>,
"linux-audit@redhat.com" <linux-audit@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 1/2] audit: Add syscall return code handling for compat task
Date: Wed, 14 Apr 2021 15:35:28 +0000 [thread overview]
Message-ID: <e3e058cb2605482d9cfcb3466d680b71@AcuMS.aculab.com> (raw)
In-Reply-To: <20210414080145.17378-1-zhe.he@windriver.com>
From: He Zhe
> Sent: 14 April 2021 09:02
>
> When 32-bit userspace application is running on 64-bit kernel, the 32-bit
> syscall return code would be changed from u32 to u64 in regs_return_value
> and then changed to s64. Hence the negative return code recorded by audit
> would end up being a big positive number like below.
>
> type=SYSCALL msg=audit(1611110715.887:582): arch=40000028 syscall=322
> success=yes exit=4294967283
>
> This patch forces the u32->s32->s64 for compat tasks.
>
> Signed-off-by: He Zhe <zhe.he@windriver.com>
> ---
> include/linux/audit.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 82b7c1116a85..32cb853f3029 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -334,7 +334,9 @@ static inline void audit_syscall_exit(void *pt_regs)
> {
> if (unlikely(audit_context())) {
> int success = is_syscall_success(pt_regs);
> - long return_code = regs_return_value(pt_regs);
> + long return_code = is_compat_task() ?
Should that be is_compat_syscall() ?
A x86-64 process can make both types of 32bit system calls.
David
> + (s64)(s32)regs_return_value(pt_regs) :
> + regs_return_value(pt_regs);
>
> __audit_syscall_exit(success, return_code);
> }
> --
> 2.17.1
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
--
Linux-audit mailing list
Linux-audit@redhat.com
https://listman.redhat.com/mailman/listinfo/linux-audit
prev parent reply other threads:[~2021-04-14 15:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-14 8:01 [PATCH 1/2] audit: Add syscall return code handling for compat task He Zhe
2021-04-14 15:35 ` David Laight [this message]
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=e3e058cb2605482d9cfcb3466d680b71@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=eparis@redhat.com \
--cc=linux-audit@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=paul@paul-moore.com \
--cc=zhe.he@windriver.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).