From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B474F4749C1; Tue, 25 Aug 2026 13:48:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787665730; cv=none; b=qLRT+atyl6bLArTBlqo7eirP7HJH+pKcjB2Z78rldQP1hxart1rHWZu18rVGpHVerUeeHLdD9lQtweXW+MQqCVrSmdJ3sruGZjRf6CGr2leBY4BRFiPKFOFLINhaTjMgsglL5N721Edyeg5dH9ET2eFlVM6mViXB3ut/801ht1A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787665730; c=relaxed/simple; bh=HYWv5noKfTQXrRn1npPXhK9G19/JZpInFemhmudpI9Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=o2XCcGztp2cj8f/Ara0ipVk3RkvvYDPwplSn8FsY2NBCmUM/hNJtyTWZrICDWTqEgm/K5EcYcuO+ETrsIRM/NG5qe6IuTHnmWYOGi7qlCueYkfeIreYWRpyrE694Pibti3G4KzSFEujND77sIHoKbc4NdDOjpWwOqmLqMjo3q+Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gonCxeLb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gonCxeLb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 173EC1F000E9; Tue, 25 Aug 2026 13:48:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787665729; bh=PalI8EhUNkEm0RKwpbM7plxKJ0UZMVOyrhM9kShfbvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gonCxeLb3NlzqciFv+wnw48EUQgzwD9MKVmFXC0Fz5eX00MgyWGgTp06/Xv5dXRRL HCgQuRfwC/YPnb8SIlKCWvNN2MR1pbYY48dSuBlRIfXwjeTl2jC1J8xLqACsZg/PSK lIoPwt3Ee43fZje54df8q/bEi6BqFEF20+iBaiK4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Samuel Page , Simon Horman , David Heidelberg Subject: [PATCH 6.6 46/87] nfc: nci: fix out-of-bounds write in nci_target_auto_activated() Date: Tue, 25 Aug 2026 15:26:09 +0200 Message-ID: <20260825132543.648943217@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.813800447@linuxfoundation.org> References: <20260825132541.813800447@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Samuel Page commit ac200079db50af81e6b04d058b33ec92901d8edd upstream. nci_target_auto_activated() appends a target to the fixed-size array ndev->targets[NCI_MAX_DISCOVERED_TARGETS] and increments ndev->n_targets without first checking the array is full; unlike its sibling nci_add_new_target(), which bails out when n_targets already equals NCI_MAX_DISCOVERED_TARGETS. ndev->n_targets is only cleared by nci_clear_target_list(), so an NFCC that repeatedly re-runs discovery (RF_DISCOVER_RSP, which re-enters NCI_DISCOVERY without clearing the target list) and reports an auto-activated target (RF_INTF_ACTIVATED_NTF) drives n_targets past the limit. The append then writes a struct nfc_target past the end of the array (a slab out-of-bounds write), and nfc_targets_found() goes on to walk the array with the inflated count: BUG: KASAN: slab-out-of-bounds in nci_add_new_protocol+0x94/0x2ac [nci] Write of size 2 at addr ffff0000c7299a18 by task kworker/u8:0/12 Workqueue: nfc0_nci_rx_wq nci_rx_work [nci] Call trace: nci_add_new_protocol+0x94/0x2ac [nci] nci_ntf_packet+0xddc/0x11a0 [nci] nci_rx_work+0x15c/0x1e0 [nci] process_one_work+0x2dc/0x500 worker_thread+0x240/0x460 kthread+0x1c0/0x1d0 ret_from_fork+0x10/0x20 The buggy address belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1024 bytes to the right of allocated 1560-byte region [ffff0000c7299000, ffff0000c7299618) Guard nci_target_auto_activated() with the same check used by nci_add_new_target(). Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support") Cc: stable@vger.kernel.org Assisted-by: Bynario AI Signed-off-by: Samuel Page Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260622145243.3167276-1-sam@bynar.io Signed-off-by: David Heidelberg Signed-off-by: Greg Kroah-Hartman --- net/nfc/nci/ntf.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/nfc/nci/ntf.c +++ b/net/nfc/nci/ntf.c @@ -603,6 +603,12 @@ static void nci_target_auto_activated(st struct nfc_target *target; int rc; + /* This is a new target, check if we've enough room */ + if (ndev->n_targets == NCI_MAX_DISCOVERED_TARGETS) { + pr_debug("not enough room, ignoring new target...\n"); + return; + } + target = &ndev->targets[ndev->n_targets]; rc = nci_add_new_protocol(ndev, target, ntf->rf_protocol,