[PATCH][v3] audit: fix a memleak caused by auditing load module

[Paul Moore]

On Thu, Mar 7, 2019 at 3:43 PM Paul Moore <paul at paul-moore.com> wrote:
> On Wed, Mar 6, 2019 at 8:16 PM Li RongQing <lirongqing at baidu.com> wrote:
> >
> > module.name will be allocated unconditionally when auditing load
> > module, and audit_log_start() can fail with other reasons, or
> > audit_log_exit maybe not called, caused module.name is not freed
> >
> > so free module.name in audit_free_context and __audit_syscall_exit
> >
> > unreferenced object 0xffff88af90837d20 (size 8):
> >   comm "modprobe", pid 1036, jiffies 4294704867 (age 3069.138s)
> >   hex dump (first 8 bytes):
> >     69 78 67 62 65 00 ff ff                          ixgbe...
> >   backtrace:
> >     [<0000000008da28fe>] __audit_log_kern_module+0x33/0x80
> >     [<00000000c1491e61>] load_module+0x64f/0x3850
> >     [<000000007fc9ae3f>] __do_sys_init_module+0x218/0x250
> >     [<0000000000d4a478>] do_syscall_64+0x117/0x400
> >     [<000000004924ded8>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
> >     [<000000007dc331dd>] 0xffffffffffffffff
> >
> > Fixes: ca86cad7380e3 ("audit: log module name on init_module")
> > Signed-off-by: Zhang Yu <zhangyu31 at baidu.com>
> > Signed-off-by: Li RongQing <lirongqing at baidu.com>
> > ---
> >
> > v3-->v2: create a helper and git rid of free from show_special as Paul suggest
> > v2-->v1: free module.name always, not check the return of audit_log_start
> >
> >  kernel/auditsc.c | 10 +++++++++-
> >  1 file changed, 9 insertions(+), 1 deletion(-)
>
> This looks better, thank you.  Once the merge window closes we can
> merge this into -next.

I just merged this into audit/next, thanks.

-- 
paul moore
www.paul-moore.com