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author | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-05-15 11:17:34 +0100 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-05-15 12:51:41 +0200 |
commit | 591054469b3eef34bc097c30fae8ededddf8d796 (patch) | |
tree | 6dfcdd522ab793a3accec95ccda1bd57d5354639 /net/netfilter/nft_immediate.c | |
parent | 71df14b0ce094be46d105b5a3ededd83b8e779a0 (diff) | |
download | linux-591054469b3eef34bc097c30fae8ededddf8d796.tar.bz2 |
netfilter: nf_tables: revisit chain/object refcounting from elements
Andreas reports that the following incremental update using our commit
protocol doesn't work.
# nft -f incremental-update.nft
delete element ip filter client_to_any { 10.180.86.22 : goto CIn_1 }
delete chain ip filter CIn_1
... Error: Could not process rule: Device or resource busy
The existing code is not well-integrated into the commit phase protocol,
since element deletions do not result in refcount decrement from the
preparation phase. This results in bogus EBUSY errors like the one
above.
Two new functions come with this patch:
* nft_set_elem_activate() function is used from the abort path, to
restore the set element refcounting on objects that occurred from
the preparation phase.
* nft_set_elem_deactivate() that is called from nft_del_setelem() to
decrement set element refcounting on objects from the preparation
phase in the commit protocol.
The nft_data_uninit() has been renamed to nft_data_release() since this
function does not uninitialize any data store in the data register,
instead just releases the references to objects. Moreover, a new
function nft_data_hold() has been introduced to be used from
nft_set_elem_activate().
Reported-by: Andreas Schultz <aschultz@tpip.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nft_immediate.c')
-rw-r--r-- | net/netfilter/nft_immediate.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c index 728baf88295a..4717d7796927 100644 --- a/net/netfilter/nft_immediate.c +++ b/net/netfilter/nft_immediate.c @@ -65,7 +65,7 @@ static int nft_immediate_init(const struct nft_ctx *ctx, return 0; err1: - nft_data_uninit(&priv->data, desc.type); + nft_data_release(&priv->data, desc.type); return err; } @@ -73,7 +73,8 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) { const struct nft_immediate_expr *priv = nft_expr_priv(expr); - return nft_data_uninit(&priv->data, nft_dreg_to_type(priv->dreg)); + + return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg)); } static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr) |