From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Date: Mon, 01 Oct 2012 13:22:25 +0000 Subject: Re: [tip:sched/numa 20/35] mm/mempolicy.c:2426 mpol_parse_str() error: buffer overflow 'policy_modes Message-Id: <1349097745.7780.13.camel@twins> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kernel-janitors@vger.kernel.org On Fri, 2012-09-28 at 19:14 +0800, Fengguang Wu wrote: > + mm/mempolicy.c:2426 mpol_parse_str() error: buffer overflow 'policy_modes' 5 <= 5 --- Subject: mm, mpol: Fix buffer overflow in mpol_parse_str() From: Peter Zijlstra Date: Mon Oct 01 15:12:16 CEST 2012 Wu reported a smatch error: + mm/mempolicy.c:2426 mpol_parse_str() error: buffer overflow 'policy_modes' 5 <= 5 Fix it by growing the array to the right size, but avoid it being a valid string for mpol_parse_str() because its not an effective policy. Reported-by: Fengguang Wu Signed-off-by: Peter Zijlstra --- mm/mempolicy.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2514,7 +2514,8 @@ static const char * const policy_modes[] [MPOL_PREFERRED] = "prefer", [MPOL_BIND] = "bind", [MPOL_INTERLEAVE] = "interleave", - [MPOL_LOCAL] = "local" + [MPOL_LOCAL] = "local", + [MPOL_NOOP] = "noop", /* should not actually be used */ }; @@ -2565,7 +2566,7 @@ int mpol_parse_str(char *str, struct mem break; } } - if (mode >= MPOL_MAX) + if (mode >= MPOL_MAX || mode = MPOL_NOOP) goto out; switch (mode) {