Messages in this thread | | | From | Paul Moore <> | Date | Wed, 12 Jan 2022 12:23:04 -0500 | Subject | Re: [PATCH] integrity: check the return value of audit_log_start() |
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On Tue, Dec 14, 2021 at 12:39 AM <xkernel.wang@foxmail.com> wrote: > > From: Xiaoke Wang <xkernel.wang@foxmail.com> > > audit_log_start() returns audit_buffer pointer on success or NULL on > error, so it is better to check the return value of it to prevent > potential memory access error. > > Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com> > --- > security/integrity/integrity_audit.c | 38 +++++++++++++++------------- > 1 file changed, 20 insertions(+), 18 deletions(-) > > diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c > index 2922005..62785d5 100644 > --- a/security/integrity/integrity_audit.c > +++ b/security/integrity/integrity_audit.c > @@ -45,23 +45,25 @@ void integrity_audit_message(int audit_msgno, struct inode *inode, > return; > > ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno);
As this is IMA code, it's largely up to Mimi about what she would prefer, but I think a much simpler patch would be to just return early if ab == NULL, for example:
ab = audit_log_start( .... , audit_msgno); if (!ab) return;
> - audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u", > - task_pid_nr(current), > - from_kuid(&init_user_ns, current_uid()), > - from_kuid(&init_user_ns, audit_get_loginuid(current)), > - audit_get_sessionid(current)); > - audit_log_task_context(ab); > - audit_log_format(ab, " op=%s cause=%s comm=", op, cause); > - audit_log_untrustedstring(ab, get_task_comm(name, current)); > - if (fname) { > - audit_log_format(ab, " name="); > - audit_log_untrustedstring(ab, fname); > + if (ab) { > + audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u", > + task_pid_nr(current), > + from_kuid(&init_user_ns, current_uid()), > + from_kuid(&init_user_ns, audit_get_loginuid(current)), > + audit_get_sessionid(current)); > + audit_log_task_context(ab); > + audit_log_format(ab, " op=%s cause=%s comm=", op, cause); > + audit_log_untrustedstring(ab, get_task_comm(name, current)); > + if (fname) { > + audit_log_format(ab, " name="); > + audit_log_untrustedstring(ab, fname); > + } > + if (inode) { > + audit_log_format(ab, " dev="); > + audit_log_untrustedstring(ab, inode->i_sb->s_id); > + audit_log_format(ab, " ino=%lu", inode->i_ino); > + } > + audit_log_format(ab, " res=%d errno=%d", !result, errno); > + audit_log_end(ab); > } > - if (inode) { > - audit_log_format(ab, " dev="); > - audit_log_untrustedstring(ab, inode->i_sb->s_id); > - audit_log_format(ab, " ino=%lu", inode->i_ino); > - } > - audit_log_format(ab, " res=%d errno=%d", !result, errno); > - audit_log_end(ab); > } > --
-- paul moore www.paul-moore.com
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