diff mbox series

[net,3/3] netfilter: nf_tables: fix memleak in map from abort path

Message ID 20240418010948.3332346-4-pablo@netfilter.org (mailing list archive)
State Accepted
Commit 86a1471d7cde792941109b93b558b5dc078b9ee9
Delegated to: Netdev Maintainers
Headers show
Series [net,1/3] netfilter: nf_tables: missing iterator type in lookup walk | expand

Checks

Context Check Description
netdev/series_format success Pull request is its own cover letter
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 942 this patch: 942
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 2 maintainers not CCed: coreteam@netfilter.org kadlec@netfilter.org
netdev/build_clang success Errors and warnings before: 937 this patch: 937
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 953 this patch: 953
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns WARNING: line length of 87 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 5 this patch: 5
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-04-18--03-00 (tests: 961)

Commit Message

Pablo Neira Ayuso April 18, 2024, 1:09 a.m. UTC
The delete set command does not rely on the transaction object for
element removal, therefore, a combination of delete element + delete set
from the abort path could result in restoring twice the refcount of the
mapping.

Check for inactive element in the next generation for the delete element
command in the abort path, skip restoring state if next generation bit
has been already cleared. This is similar to the activate logic using
the set walk iterator.

[ 6170.286929] ------------[ cut here ]------------
[ 6170.286939] WARNING: CPU: 6 PID: 790302 at net/netfilter/nf_tables_api.c:2086 nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.287071] Modules linked in: [...]
[ 6170.287633] CPU: 6 PID: 790302 Comm: kworker/6:2 Not tainted 6.9.0-rc3+ #365
[ 6170.287768] RIP: 0010:nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.287886] Code: df 48 8d 7d 58 e8 69 2e 3b df 48 8b 7d 58 e8 80 1b 37 df 48 8d 7d 68 e8 57 2e 3b df 48 8b 7d 68 e8 6e 1b 37 df 48 89 ef eb c4 <0f> 0b 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 0f
[ 6170.287895] RSP: 0018:ffff888134b8fd08 EFLAGS: 00010202
[ 6170.287904] RAX: 0000000000000001 RBX: ffff888125bffb28 RCX: dffffc0000000000
[ 6170.287912] RDX: 0000000000000003 RSI: ffffffffa20298ab RDI: ffff88811ebe4750
[ 6170.287919] RBP: ffff88811ebe4700 R08: ffff88838e812650 R09: fffffbfff0623a55
[ 6170.287926] R10: ffffffff8311d2af R11: 0000000000000001 R12: ffff888125bffb10
[ 6170.287933] R13: ffff888125bffb10 R14: dead000000000122 R15: dead000000000100
[ 6170.287940] FS:  0000000000000000(0000) GS:ffff888390b00000(0000) knlGS:0000000000000000
[ 6170.287948] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6170.287955] CR2: 00007fd31fc00710 CR3: 0000000133f60004 CR4: 00000000001706f0
[ 6170.287962] Call Trace:
[ 6170.287967]  <TASK>
[ 6170.287973]  ? __warn+0x9f/0x1a0
[ 6170.287986]  ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288092]  ? report_bug+0x1b1/0x1e0
[ 6170.287986]  ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288092]  ? report_bug+0x1b1/0x1e0
[ 6170.288104]  ? handle_bug+0x3c/0x70
[ 6170.288112]  ? exc_invalid_op+0x17/0x40
[ 6170.288120]  ? asm_exc_invalid_op+0x1a/0x20
[ 6170.288132]  ? nf_tables_chain_destroy+0x2b/0x220 [nf_tables]
[ 6170.288243]  ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288366]  ? nf_tables_chain_destroy+0x2b/0x220 [nf_tables]
[ 6170.288483]  nf_tables_trans_destroy_work+0x588/0x590 [nf_tables]

Fixes: 591054469b3e ("netfilter: nf_tables: revisit chain/object refcounting from elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d0c09f899e80..167074283ea9 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7223,6 +7223,16 @@  void nft_data_hold(const struct nft_data *data, enum nft_data_types type)
 	}
 }
 
+static int nft_setelem_active_next(const struct net *net,
+				   const struct nft_set *set,
+				   struct nft_elem_priv *elem_priv)
+{
+	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem_priv);
+	u8 genmask = nft_genmask_next(net);
+
+	return nft_set_elem_active(ext, genmask);
+}
+
 static void nft_setelem_data_activate(const struct net *net,
 				      const struct nft_set *set,
 				      struct nft_elem_priv *elem_priv)
@@ -10644,8 +10654,10 @@  static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 		case NFT_MSG_DESTROYSETELEM:
 			te = (struct nft_trans_elem *)trans->data;
 
-			nft_setelem_data_activate(net, te->set, te->elem_priv);
-			nft_setelem_activate(net, te->set, te->elem_priv);
+			if (!nft_setelem_active_next(net, te->set, te->elem_priv)) {
+				nft_setelem_data_activate(net, te->set, te->elem_priv);
+				nft_setelem_activate(net, te->set, te->elem_priv);
+			}
 			if (!nft_setelem_is_catchall(te->set, te->elem_priv))
 				te->set->ndeact--;