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 D2A5B41B8CA; Thu, 30 Jul 2026 15:01:34 +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=1785423696; cv=none; b=PG3iw+vjR3ZSY4VzDgXS2sr6uxYBALqDFw49/e7hqaiwMCWDNqE6uXi+PXtn2Dfq3aMmwjdsjpaWFxkP2G9FJtbpIXbI9KO4txujwuwZAWiHbntiHxXQ3043zzhaLk4G3t2/pkgdstIA3eRe7qGYeupuYNkGF1eRfF4jYXNfENQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785423696; c=relaxed/simple; bh=UzClH3+TGiDHNDa614fR2VmMX49OYagMschUIqe/q94=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=abc1bVywM83NJ57h7nbMeKpbdYJ+d43+1i+ShEgCdgfCe5RdyA1CACpB9BEyLexESyKj2ZNTxfgZWmGxN2G428DVluzyiX6k3+ZwXoQJAJlyhNgbOizGw67AFWmEeZDs5BzlykUbg++8tHdGcLYLr1Tqw9+ndkjHjkFtKezNyBo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Px68dOrY; 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="Px68dOrY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3046C1F00A3A; Thu, 30 Jul 2026 15:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785423694; bh=NIOhRy8nM+l9yi+IaxsSJFdniHiteV+N+g2C3l20Feg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Px68dOrY2wXQLTvMv+LMggqgsAAnu7IfcEwnJNi7dMUZxFUHuqWutCybsV3c6aHby 1B23fzDHyX3I8qHVLEtuHimHnuTbhtBs0k5Qa/jZVcjcNjgXEIBgsW9BPpN2mhQ671 BFaJWPytzecWDA3z7ciO7BxQyCYFl8Wfx/smJQsU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ivan Vecera , Vadim Fedorenko , Jiri Pirko , Paolo Abeni , Sasha Levin Subject: [PATCH 6.18 135/675] dpll: fix NULL pointer dereference in dpll_msg_add_pin_ref_sync() Date: Thu, 30 Jul 2026 16:07:45 +0200 Message-ID: <20260730141448.009544380@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141445.110192266@linuxfoundation.org> References: <20260730141445.110192266@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ivan Vecera [ Upstream commit d2e914a4a0d0f753dbae830264850d044026167c ] When a dpll_pin is shared across multiple dpll_device instances and those devices are being unregistered (e.g. during driver module removal), a NULL pointer dereference can occur in dpll_msg_add_pin_ref_sync(). This happens under the following conditions: - A pin is registered with two or more dpll devices (dpll_A, dpll_B) - The pin has ref_sync pairs with other pins - During unregistration of dpll_A's pins, a ref_sync partner pin is unregistered first, removing it from dpll_A->pin_refs - But since the partner pin is still registered with dpll_B, its dpll_refs is not empty, so dpll_pin_ref_sync_pair_del() does NOT run and the partner stays in the pin's ref_sync_pins xarray - When the pin itself is then unregistered from dpll_A, the delete notification calls dpll_msg_add_pin_ref_sync() which finds the partner in ref_sync_pins, passes dpll_pin_available() (partner is still registered with dpll_B), but dpll_pin_on_dpll_priv(dpll_A, partner) returns NULL because partner was already removed from dpll_A->pin_refs - The NULL priv pointer is passed to the driver's ref_sync_get callback, which dereferences it BUG: kernel NULL pointer dereference, address: 0000000000000034 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:zl3073x_dpll_input_pin_ref_sync_get+0x73/0x80 [zl3073x] Call Trace: dpll_msg_add_pin_ref_sync+0xb8/0x200 dpll_cmd_pin_get_one+0x3b6/0x4b0 dpll_pin_event_send+0x72/0x140 __dpll_pin_unregister+0x5a/0x2b0 dpll_pin_unregister+0x49/0x70 Fix this by skipping ref_sync pins whose priv pointer cannot be resolved for the current dpll device. Fixes: 58256a26bfb3 ("dpll: add reference sync get/set") Signed-off-by: Ivan Vecera Reviewed-by: Vadim Fedorenko Reviewed-by: Jiri Pirko Link: https://patch.msgid.link/20260710193625.1378822-1-ivecera@redhat.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/dpll/dpll_netlink.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c index de8b065280d15d..eb23ee401aaef8 100644 --- a/drivers/dpll/dpll_netlink.c +++ b/drivers/dpll/dpll_netlink.c @@ -486,6 +486,9 @@ dpll_msg_add_pin_ref_sync(struct sk_buff *msg, struct dpll_pin *pin, if (!dpll_pin_available(ref_sync_pin)) continue; ref_sync_pin_priv = dpll_pin_on_dpll_priv(dpll, ref_sync_pin); + /* Pin may have been unregistered from this dpll already */ + if (!ref_sync_pin_priv) + continue; if (WARN_ON(!ops->ref_sync_get)) return -EOPNOTSUPP; ret = ops->ref_sync_get(pin, pin_priv, ref_sync_pin, -- 2.53.0