[dpdk-dev] [PATCH v2] eal: out-of-bounds write

[dpdk-dev] [PATCH v2] eal: out-of-bounds write

[Slawomir Mrozowicz]

Fix issue reported by Coverity.

Coverity ID 13282: Out-of-bounds write
overrun-local: Overrunning array mcfg->memseg of 256 44-byte elements
at element index 257 using index j.

Fixes: af75078fece3 ("first public release")

Signed-off-by: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>
---
 lib/librte_eal/linuxapp/eal/eal_memory.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index 5b9132c..715bd52 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -1333,8 +1333,11 @@ rte_eal_hugepage_init(void)
 
 		if (new_memseg) {
 			j += 1;
-			if (j == RTE_MAX_MEMSEG)
+			if (j >= RTE_MAX_MEMSEG) {
+				RTE_LOG(ERR, EAL,
+					"Failed: memseg reached RTE_MAX_MEMSEG\n");
 				break;
+			}
 
 			mcfg->memseg[j].phys_addr = hugepage[i].physaddr;
 			mcfg->memseg[j].addr = hugepage[i].final_va;
-- 
1.9.1

Re: [dpdk-dev] [PATCH v2] eal: out-of-bounds write

[Sergio Gonzalez Monroy]

I missed this patch at the time!

On 27/04/2016 12:29, Slawomir Mrozowicz wrote:
> Fix issue reported by Coverity.
>
> Coverity ID 13282: Out-of-bounds write
> overrun-local: Overrunning array mcfg->memseg of 256 44-byte elements
> at element index 257 using index j.
>
> Fixes: af75078fece3 ("first public release")
>
> Signed-off-by: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>
> ---
>   lib/librte_eal/linuxapp/eal/eal_memory.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
> index 5b9132c..715bd52 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_memory.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
> @@ -1333,8 +1333,11 @@ rte_eal_hugepage_init(void)
>   
>   		if (new_memseg) {
>   			j += 1;
> -			if (j == RTE_MAX_MEMSEG)
> +			if (j >= RTE_MAX_MEMSEG) {
> +				RTE_LOG(ERR, EAL,
> +					"Failed: memseg reached RTE_MAX_MEMSEG\n");
>   				break;
> +			}
>   
>   			mcfg->memseg[j].phys_addr = hugepage[i].physaddr;
>   			mcfg->memseg[j].addr = hugepage[i].final_va;

As Bruce was suggesting in his comment to the v1, it's more helpful to 
do a check before the loop
and print a message distinguishing the error case, something along the 
lines of: "all memsegs
used by ivshmem. Please either increase....", returning with -ENOMEM error.

Sergio