From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793214641; b=kqmG9MgWv6qcuVRvjGISurQSi4zKvdOzE0kAY6MYtHnUiQzLCON8ERHtgeEDyIVOQurr 3I215JS8yxw0sGiGXfllcsqvPxYT81yfm4fIxLyteDHj2qwZL4gi+hvwMShAQDFkPn1XR yq2IfWS4hYqOVeOG6Ww9BCzRbA3P2mt30Ew5wHI3ckMwXwIn/B3tMwLva6WNATWGnWFpO 08h2a/f3jH5FCuiPExu6TNMnMP5g92hUeFWQupH6ipUJDOCL5mB6KOhxWveVFOZtxviAU trLNOtjEjb0gKouxjaKlvTJHJAMUDx/nesCUSI29Su2Pvp+5TFMX8HTK/nHARZvB7lg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793214641; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=WFxxcpGuac5vtrCBb9R7W1+dUPEiZZcwxnS8hm9nAmw=; b=1dbnjQaHHH9lV3/blQDA/MLSLG15Q85iDmsZn5M4MbeSO9mrlSbvvNsMVW2hy7RGYBF4 1VW9gSKX27T/cC/Nc6xYyaKGjVIShekjgecJNGzMnLCvAuurF/o9A/eESNyLVayS0RfDd aqj9IdwmFHTbnB+Fos263xgq322D537jx3JRUEwhpsSaBE7xrs/jFJUY7Fl9xhSPt5qu5 q82BHRGnz3Eqv7AeWzBNrjk7usQIXbDXxftly//hIv7jO40Up4djWBB2obgypzUbuyGxF fGyi+LmLBrBFy2kQnyLUglocMvwx9wtv3xbGPw02f0u9IStMhFbz5yKSafNWSI9SwpA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="b/O8pFPn"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E2FD3606A321; Wed, 28 Oct 2026 19:10:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=b/O8pFPn Received: by smtp.kernel.org (Postfix) with ESMTPSA id 464AA1F01825; Wed, 28 Oct 2026 19:10:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793214640; bh=WFxxcpGuac5vtrCBb9R7W1+dUPEiZZcwxnS8hm9nAmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=b/O8pFPn64VinqNjwCrmeeaFw59Q5VANgcYBcBN0Ttldu3QcKFqQ+1Sqwe0qMur05 ElMbM8Zp2PMsVUKoCXbNvc0ybjP7VOZpWnyiTtcwdS6BNVdUqWoU/Uto31rhMUS+Dy gFl+R8B4d1GVO67Jxv9nJZJOCAnx/8bjlYrHmOMs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nikolay Aleksandrov , Chen Zhen , Jussi Maki , Daniel Borkmann , Paolo Abeni , Sasha Levin Subject: [PATCH 6.1 0929/1887] bonding: fix use-after-free due to enslave fail after slave array update Date: Wed, 28 Oct 2026 17:50:25 +0100 Message-ID: <20261028170520.555826821@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikolay Aleksandrov [ Upstream commit e9acda52fd2ee0cdca332f996da7a95c5fd25294 ] Fix a use-after-free which happens due to enslave failure after the new slave has been added to the array. Since the new slave can be used for Tx immediately, we can use it after it has been freed by the enslave error cleanup path which frees the allocated slave memory. Slave update array is supposed to be called last when further enslave failures are not expected. Move it after xdp setup to avoid any problems. It is very easy to reproduce the problem with a simple xdp_pass prog: ip l add bond1 type bond mode balance-xor ip l set bond1 up ip l set dev bond1 xdp object xdp_pass.o sec xdp_pass ip l add dumdum type dummy Then run in parallel: while :; do ip l set dumdum master bond1 1>/dev/null 2>&1; done; mausezahn bond1 -a own -b rand -A rand -B 1.1.1.1 -c 0 -t tcp "dp=1-1023, flags=syn" The crash happens almost immediately: [ 605.602850] Oops: general protection fault, probably for non-canonical address 0xe0e6fc2460000137: 0000 [#1] SMP KASAN NOPTI [ 605.602916] KASAN: maybe wild-memory-access in range [0x07380123000009b8-0x07380123000009bf] [ 605.602946] CPU: 0 UID: 0 PID: 2445 Comm: mausezahn Kdump: loaded Tainted: G B 6.19.0-rc6+ #21 PREEMPT(voluntary) [ 605.602979] Tainted: [B]=BAD_PAGE [ 605.602998] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 605.603032] RIP: 0010:netdev_core_pick_tx+0xcd/0x210 [ 605.603063] Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 3e 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 6b 08 49 8d 7d 30 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 25 01 00 00 49 8b 45 30 4c 89 e2 48 89 ee 48 89 [ 605.603111] RSP: 0018:ffff88817b9af348 EFLAGS: 00010213 [ 605.603145] RAX: dffffc0000000000 RBX: ffff88817d28b420 RCX: 0000000000000000 [ 605.603172] RDX: 00e7002460000137 RSI: 0000000000000008 RDI: 07380123000009be [ 605.603199] RBP: ffff88817b541a00 R08: 0000000000000001 R09: fffffbfff3ed8c0c [ 605.603226] R10: ffffffff9f6c6067 R11: 0000000000000001 R12: 0000000000000000 [ 605.603253] R13: 073801230000098e R14: ffff88817d28b448 R15: ffff88817b541a84 [ 605.603286] FS: 00007f6570ef67c0(0000) GS:ffff888221dfa000(0000) knlGS:0000000000000000 [ 605.603319] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 605.603343] CR2: 00007f65712fae40 CR3: 000000011371b000 CR4: 0000000000350ef0 [ 605.603373] Call Trace: [ 605.603392] [ 605.603410] __dev_queue_xmit+0x448/0x32a0 [ 605.603434] ? __pfx_vprintk_emit+0x10/0x10 [ 605.603461] ? __pfx_vprintk_emit+0x10/0x10 [ 605.603484] ? __pfx___dev_queue_xmit+0x10/0x10 [ 605.603507] ? bond_start_xmit+0xbfb/0xc20 [bonding] [ 605.603546] ? _printk+0xcb/0x100 [ 605.603566] ? __pfx__printk+0x10/0x10 [ 605.603589] ? bond_start_xmit+0xbfb/0xc20 [bonding] [ 605.603627] ? add_taint+0x5e/0x70 [ 605.603648] ? add_taint+0x2a/0x70 [ 605.603670] ? end_report.cold+0x51/0x75 [ 605.603693] ? bond_start_xmit+0xbfb/0xc20 [bonding] [ 605.603731] bond_start_xmit+0x623/0xc20 [bonding] Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver") Signed-off-by: Nikolay Aleksandrov Reported-by: Chen Zhen Closes: https://lore.kernel.org/netdev/fae17c21-4940-5605-85b2-1d5e17342358@huawei.com/ CC: Jussi Maki CC: Daniel Borkmann Acked-by: Daniel Borkmann Link: https://patch.msgid.link/20260123120659.571187-1-razor@blackwall.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/bonding/bond_main.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 5b8770118c4f0..c94be63284841 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2269,11 +2269,6 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev, unblock_netpoll_tx(); } - /* broadcast mode uses the all_slaves to loop through slaves. */ - if (bond_mode_can_use_xmit_hash(bond) || - BOND_MODE(bond) == BOND_MODE_BROADCAST) - bond_update_slave_arr(bond, NULL); - if (!slave_dev->netdev_ops->ndo_bpf || !slave_dev->netdev_ops->ndo_xdp_xmit) { if (bond->xdp_prog) { @@ -2307,6 +2302,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev, bpf_prog_inc(bond->xdp_prog); } + /* broadcast mode uses the all_slaves to loop through slaves. */ + if (bond_mode_can_use_xmit_hash(bond) || + BOND_MODE(bond) == BOND_MODE_BROADCAST) + bond_update_slave_arr(bond, NULL); + slave_info(bond_dev, slave_dev, "Enslaving as %s interface with %s link\n", bond_is_active_slave(new_slave) ? "an active" : "a backup", new_slave->link != BOND_LINK_DOWN ? "an up" : "a down"); -- 2.53.0