[pkg-fetchmail-maint] Bug#416625: fetchmail: segfaults if bsmtp file can't be opened

[Reto Schuettel]

Subject: fetchmail: segfaults if bsmtp file can't be opened
Package: fetchmail
Version: 6.3.6-1
Severity: normal

fetchmail segfaults if the specified bsmtp file can't be opened (e.g. if it the parent
folder doesn't exist). 

* fetchmail manpage
|       bsmtp              -o           Specify BSMTP batch file to
|       append

I compiled fetchmail with debug symbols and I think I found the 
location of the bug.

sink.c:

 706     if (strcmp(ctl->bsmtp, "-") == 0)
 707         sinkfp = stdout;
 708     else
 709         sinkfp = fopen(ctl->bsmtp, "a");
 710 
 711     /* see the ap computation under the SMTP branch */
 712     need_anglebrs = (msg->return_path[0] != '<');
 713     fprintf(sinkfp,
 714             "MAIL FROM:%s%s%s",
 715             need_anglebrs ? "<" : "",
 716             (msg->return_path[0]) ? msg->return_path : user,
 717             need_anglebrs ? ">" : "");

I guess fetchmail should check if the open was successful :).

Program received signal SIGSEGV, Segmentation fault.
0xb7c83629 in vfprintf () from /lib/tls/i686/cmov/libc.so.6
(gdb) bt
#0  0xb7c83629 in vfprintf () from /lib/tls/i686/cmov/libc.so.6
#1  0xb7c8c212 in fprintf () from /lib/tls/i686/cmov/libc.so.6
#2  0x0805c31e in open_sink (ctl=0x8090688, msg=0x8087800, good_addresses=0xbfddcd9c, bad_addresses=0xbfddcd98) at sink.c:713
#3  0x08059b72 in readheaders (sock=6, fetchlen=2057, reallen=3795, ctl=0x8090688, num=3, suppress_readbody=0x0) at transact.c:1151
#4  0x08056682 in do_session (ctl=0x8090688, proto=0x807d000, maxfetch=0) at driver.c:621
#5  0x080685da in doIMAP (ctl=0x8090688) at imap.c:1302
#6  0x0804e87b in query_host (ctl=0x8090688) at fetchmail.c:1480
#7  0x0804f4de in main (argc=1095565372, argv=0xbfde10d4) at fetchmail.c:739

Regards,

Reto Schüttel


-- System Information:
Debian Release: 4.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.18-4-686
Locale: LANG=C, LC_CTYPE=C (charmap=ISO-8859-1) (ignored: LC_ALL set to de_CH.iso88591)

Versions of packages fetchmail depends on:
ii  adduser                     3.102        Add and remove users and groups
ii  debianutils                 2.17         Miscellaneous utilities specific t
ii  libc6                       2.3.6.ds1-13 GNU C Library: Shared libraries
ii  libssl0.9.8                 0.9.8c-4     SSL shared libraries
ii  lsb-base                    3.1-23.1     Linux Standard Base 3.1 init scrip

Versions of packages fetchmail recommends:
ii  ca-certificates               20070303   Common CA Certificates PEM files

-- no debconf information