From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Zubin Mevawalla Newsgroups: gmane.emacs.devel Subject: Null pointer dereference? Date: Fri, 12 May 2017 11:45:53 -0400 Message-ID: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-Trace: blaine.gmane.org 1494606493 11380 195.159.176.226 (12 May 2017 16:28:13 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 12 May 2017 16:28:13 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri May 12 18:28:09 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d9DQF-0002rK-HX for ged-emacs-devel@m.gmane.org; Fri, 12 May 2017 18:28:07 +0200 Original-Received: from localhost ([::1]:54547 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d9DQL-0000Mz-3V for ged-emacs-devel@m.gmane.org; Fri, 12 May 2017 12:28:13 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:41270) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d9ClR-00023c-N9 for emacs-devel@gnu.org; Fri, 12 May 2017 11:45:58 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d9ClQ-00035H-Nx for emacs-devel@gnu.org; Fri, 12 May 2017 11:45:57 -0400 Original-Received: from mail-vk0-x234.google.com ([2607:f8b0:400c:c05::234]:34111) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1d9ClQ-00031e-EI for emacs-devel@gnu.org; Fri, 12 May 2017 11:45:56 -0400 Original-Received: by mail-vk0-x234.google.com with SMTP id y190so20095306vkc.1 for ; Fri, 12 May 2017 08:45:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qbitlogic-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to; bh=nxubJ5jUgcL5En6YDIZcNgaC5ND6uuOFpNlztP6P2/s=; b=dNvSkMBG1+NbkIjIlB9cnm8zbRJ9XmKOfzZatPsZQySWio0uOmlAqb3R2L/ub+i0jT hK2zIN7wAsKPEyq5gTuFCVWP8uvgqLGIEho7GPn6JzunvZgHJV7wUYh8qTWH8kEKEiPA CTkys0l6o8b/LicVP+Y9xnZUrFOuSkR+OW7l7FhzXDynXwhGyy+/5eodLinr7Vin0tHM Uj1wNMjuB65/xDkBbaBLJwmWpZt1Y8KDqdRCXQgLjscKBqe+uGjdXoy/7ADtHzhOykEX Q0fivsFQk7K+GkXLWkHJHLWMF5xtkZf4PQ5pE3WhGGrpzGnGbMOOi2oSCCAowQX23oMV Uxmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=nxubJ5jUgcL5En6YDIZcNgaC5ND6uuOFpNlztP6P2/s=; b=uhBGPr48Pmy2f8LVx5E9bebquDTCFcP4orzNmIMB7ThD6mMMDnZXxSiUaxYeEgg5ye 7a83wB4DDp2W4FOWXEEuS/nM9QE1efmb6o7MAqIUH4GL1P3HM9oAZjf34YAJVvlOI2wJ H5MmPjLZOPyoXGFtuWlFY03ZGqJ6bf6AFR+pWHeqnHV7UJgWMgNuigoA7i3pGWFv/TYL nK1ycyX4sOrFeG80f7qkj1LGESAmFoCZSuHuofOImIqBAIlKUX3smjtZyXJ0twEEPQbm rktNJtxRAATcwnzaULh+BErpH1LzW7oCy7JHjupKfXWbfzDmRD7zFmbGA3jLOAaodnDi TOVA== X-Gm-Message-State: AODbwcCAv1XdY1cOhmpjEWSiNqX3Yf0KtdWa7+kFeOlr7uEtnfL05/Xh g3PoOEAkJJF1pbIw5MCXbKHpek2c3BdjrPc= X-Received: by 10.31.7.14 with SMTP id 14mr2091114vkh.132.1494603953796; Fri, 12 May 2017 08:45:53 -0700 (PDT) Original-Received: by 10.159.35.50 with HTTP; Fri, 12 May 2017 08:45:53 -0700 (PDT) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:400c:c05::234 X-Mailman-Approved-At: Fri, 12 May 2017 12:27:23 -0400 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:214802 Archived-At: I was curious if this was a real null pointer dereference issue, in etags.c on line 2265? `np_parent` is initialized to NULL on 2248. if `np` is not NULL and `np->fdp == badfdp` then `np_parent->left` on line 2265 would result in a null pointer dereference. CodeAi, an automated repair tool being developed at Qbit logic, suggested a condition tightening as a fix. diff --git a/lib-src/etags.c b/lib-src/etags.c index 015cbbe..1f50d06 100644 --- a/lib-src/etags.c +++ b/lib-src/etags.c @@ -2260,7 +2260,7 @@ invalidate_nodes (fdesc *badfdp, node **npp) np_parent = np; np = np->left; } - if (np) + if (np_parent && (np)) { np_parent->left = np->left; /* detach subtree from the tree */ np->left = NULL; /* isolate it */ Could I submit this as a patch if it looks alright? Thanks so much, Zubin