2021-07-17 11:31:54

by Pavel Skripkin

Subject: [PATCH] net: sched: fix memory leak in tcindex_partial_destroy_work

Syzbot reported memory leak in tcindex_set_parms(). The problem was in
non-freed perfect hash in tcindex_partial_destroy_work().

In tcindex_set_parms() new tcindex_data is allocated and some fields from
old one are copied to new one, but not the perfect hash. Since
tcindex_partial_destroy_work() is the destroy function for old
tcindex_data, we need to free perfect hash to avoid memory leak.

Reported-and-tested-by: [email protected]
Fixes: 331b72922c5f ("net: sched: RCU cls_tcindex")
Signed-off-by: Pavel Skripkin <[email protected]>
---
net/sched/cls_tcindex.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index c4007b9cd16d..7ffc7be1e05d 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -278,6 +278,8 @@ static int tcindex_filter_result_init(struct tcindex_filter_result *r,
TCA_TCINDEX_POLICE);
}

+static void tcindex_free_perfect_hash(struct tcindex_data *cp);
+
static void tcindex_partial_destroy_work(struct work_struct *work)
{
struct tcindex_data *p = container_of(to_rcu_work(work),
@@ -285,7 +287,8 @@ static void tcindex_partial_destroy_work(struct work_struct *work)
rwork);

rtnl_lock();
- kfree(p->perfect);
+ if (p->perfect)
+ tcindex_free_perfect_hash(p);
kfree(p);
rtnl_unlock();
}
--
2.32.0

2021-07-18 16:51:13

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] net: sched: fix memory leak in tcindex_partial_destroy_work

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Sat, 17 Jul 2021 14:29:33 +0300 you wrote:
> Syzbot reported memory leak in tcindex_set_parms(). The problem was in
> non-freed perfect hash in tcindex_partial_destroy_work().
>
> In tcindex_set_parms() new tcindex_data is allocated and some fields from
> old one are copied to new one, but not the perfect hash. Since
> tcindex_partial_destroy_work() is the destroy function for old
> tcindex_data, we need to free perfect hash to avoid memory leak.
>
> [...]

Here is the summary with links:
- net: sched: fix memory leak in tcindex_partial_destroy_work
https://git.kernel.org/netdev/net/c/f5051bcece50

You are awesome, thank you!
--
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