From: "Zhao1, Wei" <wei.zhao1@intel.com>
To: "Ye, Xiaolong" <xiaolong.ye@intel.com>, "Guo, Jia" <jia.guo@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"stable@dpdk.org" <stable@dpdk.org>,
"Xing, Beilei" <beilei.xing@intel.com>
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] net/i40e: fix the security risk of wild pointer operation
Date: Mon, 18 May 2020 05:24:51 +0000 [thread overview]
Message-ID: <MWHPR11MB13914F2D05C4A7AD116D10EFB7B80@MWHPR11MB1391.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20200515072806.GC1064@intel.com>
HI, Xiaolong & guojia
> -----Original Message-----
> From: Ye, Xiaolong <xiaolong.ye@intel.com>
> Sent: Friday, May 15, 2020 3:28 PM
> To: Guo, Jia <jia.guo@intel.com>
> Cc: Zhao1, Wei <wei.zhao1@intel.com>; dev@dpdk.org; stable@dpdk.org;
> Xing, Beilei <beilei.xing@intel.com>
> Subject: Re: [dpdk-dev] [PATCH] net/i40e: fix the security risk of wild pointer
> operation
>
> On 05/15, Jeff Guo wrote:
> >hi, zhaowei
> >
> >On 5/12/2020 11:19 PM, Wei Zhao wrote:
> >> In i40e PMD code of function i40e_res_pool_free(), if valid_entry is
> >> freed by "rte_free(valid_entry);" in the following code:
> >>
> >> if (prev != NULL) {
> >> ........................
> >>
> >> if (insert == 1) {
> >> LIST_REMOVE(valid_entry, next);
> >> rte_free(valid_entry);
> >> } else {
> >> rte_free(valid_entry);
> >> insert = 1;
> >> }
> >> }
> >>
> >> then the following code for pool update may still use the wild
> >> pointer
> >> "valid_entry":
> >>
> >> " pool->num_free += valid_entry->len;
> >> pool->num_alloc -= valid_entry>len; "
> >> it seems to be a security bug, we should avoid this risk.
> >>
> >> Cc: stable@dpdk.org
> >> Fixes: 4861cde46116 ("i40e: new poll mode driver")
> >>
> >> Signed-off-by: Wei Zhao <wei.zhao1@intel.com>
> >> ---
> >> drivers/net/i40e/i40e_ethdev.c | 6 +++---
> >> 1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/net/i40e/i40e_ethdev.c
> >> b/drivers/net/i40e/i40e_ethdev.c index 749d85f54..7f8ea5309 100644
> >> --- a/drivers/net/i40e/i40e_ethdev.c
> >> +++ b/drivers/net/i40e/i40e_ethdev.c
> >> @@ -4973,6 +4973,9 @@ i40e_res_pool_free(struct i40e_res_pool_info
> *pool,
> >> }
> >> insert = 0;
> >> + pool->num_free += valid_entry->len;
> >> + pool->num_alloc -= valid_entry->len;
> >> +
> >
> >
> >Shouldn't the pool count update after the pool->free_list updated by
> >"LIST_INSERT_HEAD(&pool->free_list, valid_entry, next)"?
> >
> >If so, you could use a variable to restore valid_entry->len at the
> >begin and use it update pool count and other place.
>
> Either way works from function point of view, but I do agree with Jeff that uses
> local variable to store the valid_entry->len at the beginning, and then updates
> the pool->num_free/num_alloc at the end.
>
> Also I think it needs to set valid_entry to NULL after free it, it can avoid wild
> pointer case like this, if there is dereference of this pointer after setting it to
> NULL, program would crash directly and we can solve it early.
>
> Thanks,
> Xiaolong
We must update it after find the proper one in the pool->free_list at once, if we use a local pointer to store it,
The proper entry may has been freed in the following code, and merge with other free resource prev or next.
>
> >
> >
> >> /* Try to merge with next one*/
> >> if (next != NULL) {
> >> /* Merge with next one */
> >> @@ -5010,9 +5013,6 @@ i40e_res_pool_free(struct i40e_res_pool_info
> *pool,
> >> LIST_INSERT_HEAD(&pool->free_list, valid_entry, next);
> >> }
> >> - pool->num_free += valid_entry->len;
> >> - pool->num_alloc -= valid_entry->len;
> >> -
> >> return 0;
> >> }
next prev parent reply other threads:[~2020-05-18 5:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 15:19 [dpdk-stable] " Wei Zhao
2020-05-15 2:24 ` Zhao1, Wei
2020-05-15 6:32 ` [dpdk-stable] [dpdk-dev] " Jeff Guo
2020-05-15 7:28 ` Ye Xiaolong
2020-05-18 5:24 ` Zhao1, Wei [this message]
2020-05-18 5:32 ` Ye Xiaolong
2020-05-18 5:10 ` [dpdk-stable] [PATCH v2] net/i40e: fix the core dump " Wei Zhao
2020-05-18 6:43 ` [dpdk-stable] [PATCH v3] " Wei Zhao
2020-05-18 7:43 ` [dpdk-stable] [PATCH v4] " Wei Zhao
2020-05-18 8:00 ` [dpdk-stable] [PATCH v5] " Wei Zhao
2020-05-18 8:45 ` Jeff Guo
2020-05-19 1:28 ` Ye Xiaolong
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=MWHPR11MB13914F2D05C4A7AD116D10EFB7B80@MWHPR11MB1391.namprd11.prod.outlook.com \
--to=wei.zhao1@intel.com \
--cc=beilei.xing@intel.com \
--cc=dev@dpdk.org \
--cc=jia.guo@intel.com \
--cc=stable@dpdk.org \
--cc=xiaolong.ye@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).