From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out203-205-221-236.mail.qq.com (out203-205-221-236.mail.qq.com [203.205.221.236]) (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 BA00E146D6A for ; Tue, 18 Mar 2025 09:25:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.205.221.236 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742289964; cv=none; b=FSLtJfzIxr12N3wsinGBK9WErSWaumOsztbT0teWxBlz+b4iCJgGvJeClkOyfGpJBosb8MeFUCM3kXgUKdkrqeWYftFXC8lStwKhbBr5vQV64JVB0tsrAHouoaxS0MTsgoe9/MUBHt+OzoI4CCLVq+Tk+ljq7CThjE/lGBMW49A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742289964; c=relaxed/simple; bh=A7i3cr40fDVNDgpy8XKVzETKYkek8jHslUVV7CN4Y2M=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=FLm+7pMd4coakTlAxXOxpV1fcze32k6HhcqnSGt9VKFk3XTIckGAKO6sSIxbuQ9Wrvs3cerzmQZ5bIjeWn5bmH98UiH06dDk6o+D5D9doG+HxqLwbc5++NOgpyueANrRavsw9broaUDG01vH5T5loUTUcuWuKj+B2SANap1BbHc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=va/9/zTN; arc=none smtp.client-ip=203.205.221.236 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="va/9/zTN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1742289950; bh=bAjNfmWg9KBxVI6rssw95BWZMVE+YYRwt/FLUXMcm4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=va/9/zTNDRhDz4p0cneCCXA8kSwmENkuUhbMP00FXjQmTp/YB1+bX+hK8UdKNmsY3 rXjZYyIGMHX3DukNvNQRl3FGtRNACDXnJCb9O1cq+/VeiXG6kMKO/hbOpo1u2byeth 2Nl5C4f35NhcGxvZaWrx1ILzdTlOZqK/gZ7UVB4o= Received: from pek-lxu-l1.wrs.com ([114.244.57.157]) by newxmesmtplogicsvrszc16-0.qq.com (NewEsmtp) with SMTP id 44DAC8B1; Tue, 18 Mar 2025 17:17:13 +0800 X-QQ-mid: xmsmtpt1742289433tcuj20p0g Message-ID: X-QQ-XMAILINFO: OZZSS56D9fAjU+YeLrlU/G3Id+qMYypBtWlnKWbAl3WPxYL6P2DHuPuZCHm7Dw HKyyYbKc0smxMrKnojQAPLQTehZnl+iXfracfvU6qkSKZRLj4OltYriyiM6ArT8Yf1xS2Psx16vg 8lN5NyhmqKXUClGBcAPEc2hAdhYbBYt9hp3fgJhVafFXmUR1uoQkCXL68OXsN2zUJelMIIf/PUyY ANqdtC4O0JIPBQtQE3YuI/Gv1KPrIS/7Vl+e4brFhr8WVgMpUVbrmyUwkjiE1jOTi55k/bmsSePg SCefxug+YANJjRCjR6Zr9Yp10+aQZ+ncTFGxlpoDUeNch8zDnPV7LOEot+1JlAQkCf9lYy3zrjIA eyFsHB+0t7Ydz7l9xYUDRvg0XQXbprjPfzP5L8cKDUBiAfK8ZilTsI2X4WjVaob39bgir0y/gJGo YCcnAPpJvApdR9EHeIwU0UKaqaMJEhd0G3fCuCXbVKBNWDGuxh6gBeccxp+Y9Fck6o0VY0vLF/me KS2rB0Py312Tg8pvyvFjZDPjBK6pqP3zxFnzsF7YBgIGnOpKr2tnOnaWUU9gWQAJhsQPhDRTknOR FLUPeJPVXY0eYpIoIMdQUV6krphAF8Vd/CGMVjXr+NRoQTPWxm4T/kdUHmEBZVbcj6CwlLdMvVDi 6NMB6aBBMv9bSlPDtEBV2D3afh9qxEDF39Yr5LMs1S5l64QYkSLaxuLOes46A3ppDGXjARmBN+uh GnnlVq44pZkYITy5QAnDyPMnGenZ1TYl1YxLtuz4GVvoN5Y0nsx9l2UFn1jIkhN+C0nrMBwcypji UeisJ1V5GLZ/nv77jC7z2/wSCEH4eHYfoBTjKW452Ltu9AHR+k1A2FaP2uFJqF2Ts2DJCRCsu3vA FAjsPYWjpjVIAScmldvp5ChwE1WpSzeTj8njYNC9AVZieFfyrbG60= X-QQ-XMRINFO: NyFYKkN4Ny6FSmKK/uo/jdU= From: Edward Adam Davis To: syzbot+76a6f18e3af82e84f264@syzkaller.appspotmail.com Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [afs?] general protection fault in afs_atcell_get_link Date: Tue, 18 Mar 2025 17:17:14 +0800 X-OQ-MSGID: <20250318091713.3473902-2-eadavis@qq.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <67d92a74.050a0220.2ca2c6.014f.GAE@google.com> References: <67d92a74.050a0220.2ca2c6.014f.GAE@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit #syz test diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c index 008698d706ca..7d997f7a8028 100644 --- a/fs/afs/dynroot.c +++ b/fs/afs/dynroot.c @@ -314,6 +314,9 @@ static const char *afs_atcell_get_link(struct dentry *dentry, struct inode *inod const char *name; bool dotted = vnode->fid.vnode == 3; + if (!rcu_access_pointer(net->ws_cell)) + return ERR_PTR(-ENOENT); + if (!dentry) { /* We're in RCU-pathwalk. */ cell = rcu_dereference(net->ws_cell); @@ -325,9 +328,6 @@ static const char *afs_atcell_get_link(struct dentry *dentry, struct inode *inod return name; } - if (!rcu_access_pointer(net->ws_cell)) - return ERR_PTR(-ENOENT); - down_read(&net->cells_lock); cell = rcu_dereference_protected(net->ws_cell, lockdep_is_held(&net->cells_lock));