Messages in this thread | | | Subject | Re: [PATCH v2] consolemap: Fix a memory leaking bug in drivers/tty/vt/consolemap.c | From | Jon Hunter <> | Date | Fri, 24 May 2019 10:37:59 +0100 |
| |
Kees,
On 23/05/2019 17:54, Kees Cook wrote: > On Thu, May 23, 2019 at 08:34:52AM +0800, Gen Zhang wrote: >> In function con_insert_unipair(), when allocation for p2 and p1[n] >> fails, ENOMEM is returned, but previously allocated p1 is not freed, >> remains as leaking memory. Thus we should free p1 as well when this >> allocation fails. >> >> Signed-off-by: Gen Zhang <blackgod016574@gmail.com> > > As far as I can see this is correct, as it's just restoring the prior > state before the p1 allocation.
Are you sure this is correct? It looks like p1 is only allocated if p->uni_pgdir[n = unicode >> 11] == NULL.
I only mention this because I have seen a few patches from Gen today regarding memory leaks and devm_kzalloc() that are not correct.
> Reviewed-by: Kees Cook <keescook@chromium.org> > >> --- >> diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c >> index b28aa0d..79fcc96 100644 >> --- a/drivers/tty/vt/consolemap.c >> +++ b/drivers/tty/vt/consolemap.c >> @@ -489,7 +489,11 @@ con_insert_unipair(struct uni_pagedir *p, u_short unicode, u_short fontpos) >> p2 = p1[n = (unicode >> 6) & 0x1f]; >> if (!p2) { >> p2 = p1[n] = kmalloc_array(64, sizeof(u16), GFP_KERNEL); >> - if (!p2) return -ENOMEM; >> + if (!p2) { >> + kfree(p1); >> + p->uni_pgdir[n] = NULL; >> + return -ENOMEM; >> + } >> memset(p2, 0xff, 64*sizeof(u16)); /* No glyphs for the characters (yet) */ >> } >> >> ---
Cheers Jon
-- nvpublic
| |