Bug#355047: apt tools segfault

To: "Debian Bug Tracking System" <355047@bugs.debian.org>
Subject: Bug#355047: apt tools segfault
From: "Josep M. Perez Cancer" <josep.m.perez@bsc.es>
Date: Fri, 14 Jul 2006 11:21:03 +0200
Message-id: <[🔎] 44B761FF.50506@bsc.es>
Reply-to: "Josep M. Perez Cancer" <josep.m.perez@bsc.es>, 355047@bugs.debian.org

Followup-For: Bug #355047
Package: apt
Version: 0.6.44.2

*** Please type your report below this line ***
apt-get and apt-cache segfault at the same program location. In the case
of apt-get, update finishes with a segfault and upgrade segfaults while
reading the package list. In the apt-cache case, just doing a search
triggers the segfault.

I have recompiled the package without optimisation and without
stripping and run it through gdb and strace.


-- Debugging session follows:
$ gdb apt-cache
GNU gdb 6.4.90-debian
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are

welcome to change it and/or distribute copies of it under certainconditions.

Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i486-linux-gnu"...Using host libthread_db
library "/lib/tls/i686/cmov/libthread_db.so.1".

(gdb) run search apt
Starting program: /usr/bin/apt-cache search apt

Program received signal SIGSEGV, Segmentation fault.
0xa7c60ca3 in strlen () from /lib/tls/i686/cmov/libc.so.6
(gdb) bt
#0  0xa7c60ca3 in strlen () from /lib/tls/i686/cmov/libc.so.6
#1  0xa7deb5c6 in std::string::compare () from /usr/lib/libstdc++.so.6

#2 0xa7e9ea7a in std::operator!=<char, std::char_traits<char>,std::allocator<char> > (__lhs=@0xafb5aa1c, __rhs=0x0)at/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/basic_string.h:2200#3 0xa7f037d5 in debPackagesIndex::FindInCache (this=0x805b270,Cache=@0xafb5aa94) at deb/debindexfile.cc:308#4 0xa7ecbb30 in CheckValidity (CacheFile=@0xafb5acd8,Start={_M_current = 0x805c528}, End={_M_current = 0x805c55c},OutMap=0xafb5afd8)

   at pkgcachegen.cc:580

#5 0xa7ece980 in pkgMakeStatusCache (List=@0x805baf8,Progress=@0xafb5af78, OutMap=0xafb5afd8, AllowMem=true) atpkgcachegen.cc:715

#6  0x0804d307 in main (argc=3, argv=0xafb5b094) at apt-cache.cc:1791
(gdb) frame 3

#3 0xa7f037d5 in debPackagesIndex::FindInCache (this=0x805b270,Cache=@0xafb5aa94) at deb/debindexfile.cc:308

308           if (FileName != File.FileName())
(gdb) print FileName

$1 = {static npos = 4294967295, _M_dataplus = {<std::allocator<char>> ={<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>},_M_p = 0x805c884"/var/lib/apt/lists/ftp.nl.debian.org_debian_dists_unstable_main_binary-i386_Packages"}}

(gdb) print File
$2 = {Owner = 0xafb5aa94, File = 0xa7f44220}
(gdb) print File.Owner
$3 = (class pkgCache *) 0xafb5aa94
(gdb) print *File.Owner

$4 = {_vptr.pkgCache = 0x805a468, CacheFile = {static npos = 4294967295,_M_dataplus = {<std::allocator<char>> ={<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No datafields>}, _M_p = 0xa7e395bc ""}},Map = @0x805c6c8, HeaderP = 0xa7f42000, PkgP = 0xa7f42000,VerFileP = 0xa7f42000, PkgFileP = 0xa7f42000, VerP = 0xa7f42000,ProvideP = 0xa7f42000, DepP = 0xa7f42000, StringItemP = 0xa7f42000,StrP = 0xa7f42000 "\230\004", VS = 0xa7f29ca4}

(gdb) print *File.File

$5 = {FileName = 0, Archive = 0, Component = 0, Version = 0, Origin = 0,Label = 0, Architecture = 0, Site = 0, IndexType = 0, Size = 0,

 Flags = 0, NextFile = 0, ID = 0, mtime = 0}
(gdb) up

#4 0xa7ecbb30 in CheckValidity (CacheFile=@0xafb5acd8,Start={_M_current = 0x805c528}, End={_M_current = 0x805c55c},OutMap=0xafb5afd8)

   at pkgcachegen.cc:580
580           pkgCache::PkgFileIterator File = (*Start)->FindInCache(Cache);
(gdb) frame 3

#3 0xa7f037d5 in debPackagesIndex::FindInCache (this=0x805b270,Cache=@0xafb5aa94) at deb/debindexfile.cc:308

308           if (FileName != File.FileName())
(gdb) print *this

$6 = {<pkgIndexFile> = {_vptr.pkgIndexFile = 0xa7f27048, Trusted =true}, URI = {static npos = 4294967295,_M_dataplus = {<std::allocator<char>> ={<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>},_M_p = 0x805bb44 "http://ftp.nl.debian.org/debian/"}}, Dist ={static npos = 4294967295,_M_dataplus = {<std::allocator<char>> ={<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>},

     _M_p = 0x805be5c "unstable"}}, Section = {static npos = 4294967295,

_M_dataplus = {<std::allocator<char>> ={<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No datafields>}, _M_p = 0x805babc "main"}}}

(gdb)


-- strace output
$ strace apt-cache search apt

execve("/usr/bin/apt-cache", ["apt-cache", "search", "apt"], [/* 31 vars*/]) = 0

uname({sys="Linux", node="bscig02", ...}) = 0
brk(0)                                  = 0x805b000

access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file ordirectory)mmap2(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,0) = 0xa7fab000access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file ordirectory)

open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=108031, ...}) = 0
mmap2(NULL, 108031, PROT_READ, MAP_PRIVATE, 3, 0) = 0xa7f90000
close(3)                                = 0