| Message ID | tencent_425C87AB28D1FF53823C3047E48A71FC520A@qq.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | integrity: check the return value of audit_log_start() | expand |
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); > } > --
On Wed, 2022-01-12 at 12:23 -0500, Paul Moore wrote: > 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; Thanks, Paul. Neither the linux-integrity mailing list nor I were Cc'ed on this. Looks like the IMA & EVM records in MAINTAINERS should be updated to include the security/integrity directory. thanks, Mimi
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); - 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); }