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| author | valis <sec@valis.email> | 2023-07-29 08:32:00 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-11 11:45:37 +0200 |
| commit | 4aae24015ecd70d824a953e2dc5b0ca2c4769243 (patch) | |
| tree | f8200030a3532cb087c747e2ac2a7200de03ff57 /net | |
| parent | 2649ce3bc0e7d638b179cff1d97054e4066f0ae2 (diff) | |
| download | linux-4aae24015ecd70d824a953e2dc5b0ca2c4769243.tar.gz linux-4aae24015ecd70d824a953e2dc5b0ca2c4769243.tar.bz2 linux-4aae24015ecd70d824a953e2dc5b0ca2c4769243.zip | |
net/sched: cls_u32: No longer copy tcf_result on update to avoid use-after-free
[ Upstream commit 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81 ]
When u32_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.
This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.
Fix this by no longer copying the tcf_result struct from the old filter.
Fixes: de5df63228fc ("net: sched: cls_u32 changes to knode must appear atomic to readers")
Reported-by: valis <sec@valis.email>
Reported-by: M A Ramdhan <ramdhan@starlabs.sg>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg>
Link: https://lore.kernel.org/r/20230729123202.72406-2-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/cls_u32.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 5e052c7342b9..1e71ff093c91 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -879,7 +879,6 @@ static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp, new->ifindex = n->ifindex; #endif new->fshift = n->fshift; - new->res = n->res; new->flags = n->flags; RCU_INIT_POINTER(new->ht_down, ht); |