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From: Nick Clifton <nickc@redhat.com>
To: Tulio Magno Quites Machado Filho <tuliom@ascii.art.br>,
	annobin@sourceware.org
Subject: Re: [PATCH] Fix known_glibc_specials comparison
Date: Fri, 14 Jun 2024 09:53:14 +0100	[thread overview]
Message-ID: <05c81419-9577-469a-a8e7-7cccea0be9fc@redhat.com> (raw)
In-Reply-To: <20240613180811.126880-1-tuliom@ascii.art.br>

[-- Attachment #1: Type: text/plain, Size: 832 bytes --]

Hi Tulio,

> Sometimes variable path stores a longer path instead of just the name of
> a file, e.g. /usr/lib/libfoo.so instead of libfoo.so.

Err, I think, based upon your code you mean that path should be "usr/lib/libfoo.so"
instead of just "libfoo.so".  (ie without the leading forward slash - there is
already code at the start of is_special_glibc_binary that handles absolute paths).

> In those cases, we need to remove all the directories before calling
> strcmp().

I am reluctant to accept this change because it would treat, eg "build/getent"
as a glibc binary when it almost certainly should not.  I would prefer it if
only a known set of path prefixes were allowed.

Instead, would you mind trying out the attached alternative patch and let me
know if it solves the problem that you were investigating ?

Cheers
   Nick

[-- Attachment #2: glibc-abs-path.patch --]
[-- Type: text/x-patch, Size: 1533 bytes --]

diff --git a/annocheck/hardened.c b/annocheck/hardened.c
index 604b6a1..deeb084 100644
--- a/annocheck/hardened.c
+++ b/annocheck/hardened.c
@@ -1895,30 +1895,32 @@ is_special_glibc_binary (annocheck_data * data)
 	  return true;
     }
 
-  /* If we are testing an uninstalled rpm then the paths will start with "."
-     so skip this.  */
+  /* If we are testing an uninstalled rpm then the paths will probably
+     start with "." so skip this.  */
   if (path[0] == '.')
     ++path;
-
   if (path[0] == '/')
+    ++path;
+  /* Look for absolute paths to known glibc install locations.
+     If found, strip the prefix.
+     This allows us to cope with symbolic links and 32-bit/64-bit multilibs.  */
+  if (strchr (path, '/'))
     {
-      /* If the path is absolute, then strip the prefix.
-	 This allows us to cope with symbolic links and 32-bit/64-bit multilibs.  */
       static const char * known_prefixes [] =
 	{
 	  /* NB/ The terminating forward slash is important.  */
-	  "/lib/",
-	  "/lib64/",
-	  "/sbin/",
-	  "/usr/bin/",
-	  "/usr/lib/",
-	  "/usr/lib/gconv/",
-	  "/usr/lib64/",
-	  "/usr/lib64/gconv/",
-	  "/usr/lib64/glibc-hwcaps/power10/",
-	  "/usr/libexec/",
-	  "/usr/libexec/getconf/",
-	  "/usr/sbin/"
+	  "lib/",
+	  "lib64/",
+	  "sbin/",
+	  "usr/bin/",
+	  "usr/lib/",
+	  "usr/lib/gconv/",
+	  "usr/lib64/",
+	  "usr/lib64/gconv/",
+	  "usr/lib64/glibc-hwcaps/power10/",
+	  "usr/libexec/",
+	  "usr/libexec/getconf/",
+	  "usr/sbin/"
 	};
 
       for (i = ARRAY_SIZE (known_prefixes); i--;)

  reply	other threads:[~2024-06-14  8:53 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-13 18:08 Tulio Magno Quites Machado Filho
2024-06-14  8:53 ` Nick Clifton [this message]
2024-06-14 12:28   ` Tulio Magno Quites Machado Filho

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