KNOWNBUGS revision 141858
15084Sjohnlev 25084Sjohnlev 35084Sjohnlev K N O W N B U G S I N S E N D M A I L 45084Sjohnlev 55084Sjohnlev 65084SjohnlevThe following are bugs or deficiencies in sendmail that we are aware of 75084Sjohnlevbut which have not been fixed in the current release. You probably 85084Sjohnlevwant to get the most up to date version of this from ftp.sendmail.org 95084Sjohnlevin /pub/sendmail/KNOWNBUGS. For descriptions of bugs that have been 105084Sjohnlevfixed, see the file RELEASE_NOTES (in the root directory of the sendmail 115084Sjohnlevdistribution). 125084Sjohnlev 135084SjohnlevThis list is not guaranteed to be complete. 145084Sjohnlev 155084Sjohnlev* Delivery to programs that generate too much output may cause problems 165084Sjohnlev 175084Sjohnlev If e-mail is delivered to a program which generates too much 185084Sjohnlev output, then sendmail may issue an error: 195084Sjohnlev 205084Sjohnlev timeout waiting for input from local during Draining Input 215084Sjohnlev 225084Sjohnlev Make sure that the program does not generate output beyond a 2311588Sdavid.edmondson@sun.com status message (corresponding to the exit status). This may 245084Sjohnlev require a wrapper around the actual program to redirect output 255084Sjohnlev to /dev/null. 265084Sjohnlev 275084Sjohnlev Such a problem has been reported for bulk_mailer. 285084Sjohnlev 295084Sjohnlev* Null bytes are not handled properly in headers. 305084Sjohnlev 315084Sjohnlev Sendmail should handle full binary data. As it stands, it handles 325084Sjohnlev all values in the body, but only 0x01-0x80 and 0xA0-0xFF in 335084Sjohnlev the header. Notably missing is 0x00, which would require a major 345084Sjohnlev restructuring of the code -- for example, almost no C library support 355084Sjohnlev could be used to handle strings. 365084Sjohnlev 375084Sjohnlev* Header checks are not called if header value is too long or empty. 385084Sjohnlev 395084Sjohnlev If the value of a header is longer than 1250 (MAXNAME + MAXATOM - 6) 405084Sjohnlev characters or it contains a single word longer than 256 (MAXNAME) 415084Sjohnlev characters then no header check is done even if one is configured for 425084Sjohnlev the header. 435084Sjohnlev 445084Sjohnlev* Header lines which are too long will be split incorrectly. 455084Sjohnlev 465084Sjohnlev Header lines which are longer than 2045 characters will be split 475084Sjohnlev but some characters might be lost. Fix: obey RFC (2)822 and do not 485084Sjohnlev send lines that are longer than 1000 characters. 495084Sjohnlev 505084Sjohnlev* Sender addresses whose domain part cause a temporary A record lookup 515084Sjohnlev failure but have a valid MX record will be temporarily rejected in 525084Sjohnlev the default configuration. Solution: fix the DNS at the sender side. 535084Sjohnlev If that's not easy to achieve, possible workarounds are: 545084Sjohnlev - add an entry to the access map: 555084Sjohnlev dom.ain OK 565084Sjohnlev - (only for advanced users) replace 575084Sjohnlev 585084Sjohnlev# Resolve map (to check if a host exists in check_mail) 5910643Stim.foster@sun.comKresolve host -a<OKR> -T<TEMP> 6010643Stim.foster@sun.com 6110643Stim.foster@sun.com with 6210643Stim.foster@sun.com 6310643Stim.foster@sun.com# Resolve map (to check if a host exists in check_mail) 6410643Stim.foster@sun.comKcanon host -a<OKR> -T<TEMP> 6511588Sdavid.edmondson@sun.comKdnsmx dns -R MX -a<OKR> -T<TEMP> 665084SjohnlevKresolve sequence dnsmx canon 6711588Sdavid.edmondson@sun.com 685084Sjohnlev 695084Sjohnlev* Duplicate error messages. 705084Sjohnlev 715084Sjohnlev Sometimes identical, duplicate error messages can be generated. As 725084Sjohnlev near as I can tell, this is rare and relatively innocuous. 735084Sjohnlev 745084Sjohnlev* Misleading error messages. 755084Sjohnlev 765084Sjohnlev If an illegal address is specified on the command line together 775084Sjohnlev with at least one valid address and PostmasterCopy is set, the 785084Sjohnlev DSN does not contain the illegal address, but only the valid 795084Sjohnlev address(es). 805084Sjohnlev 815084Sjohnlev* \231 considered harmful. 825084Sjohnlev 835084Sjohnlev Header addresses that have the \231 character (and possibly others 845084Sjohnlev in the range \201 - \237) behave in odd and usually unexpected ways. 855084Sjohnlev 865084Sjohnlev* accept() problem on SVR4. 875084Sjohnlev 885084Sjohnlev Apparently, the sendmail daemon loop (doing accept()s on the network) 895084Sjohnlev can get into a weird state on SVR4; it starts logging ``SYSERR: 905084Sjohnlev getrequests: accept: Protocol Error''. The workaround is to kill 915084Sjohnlev and restart the sendmail daemon. We don't have an SVR4 system at 925084Sjohnlev Berkeley that carries more than token mail load, so I can't validate 935084Sjohnlev this. It is likely to be a glitch in the sockets emulation, since 9410643Stim.foster@sun.com "Protocol Error" is not possible error code with Berkeley TCP/IP. 955084Sjohnlev 965084Sjohnlev I've also had someone report the message ``sendmail: accept: 975084Sjohnlev SIOCGPGRP failed errno 22'' on an SVR4 system. This message is 985084Sjohnlev not in the sendmail source code, so I assume it is also a bug 995084Sjohnlev in the sockets emulation. (Errno 22 is EINVAL "Invalid Argument" 1005084Sjohnlev on all the systems I have available, including Solaris 2.x.) 1015084Sjohnlev Apparently, this problem is due to linking -lc before -lsocket; 1025084Sjohnlev if you are having this problem, check your Makefile. 1035084Sjohnlev 104* accept() problem on Linux. 105 106 The accept() in sendmail daemon loop can return ETIMEDOUT. An 107 error is reported to syslog: 108 109 Jun 9 17:14:12 hostname sendmail[207]: NOQUEUE: SYSERR(root): 110 getrequests: accept: Connection timed out 111 112 "Connection timed out" is not documented as a valid return from 113 accept(2) and this was believed to be a bug in the Linux kernel. 114 Later information from the Linux kernel group states that Linux 115 2.0 kernels follow RFC1122 while sendmail follows the original BSD 116 (now POSIX 1003.1g draft) specification. The 2.1.X and later kernels 117 will follow the POSIX draft. 118 119* Excessive mailing list nesting can run out of file descriptors. 120 121 If you have a mailing list that includes lots of other mailing 122 lists, each of which has a separate owner, you can run out of 123 file descriptors. Each mailing list with a separate owner uses 124 one open file descriptor (prior to 8.6.6 it was three open 125 file descriptors per list). This is particularly egregious if 126 you have your connection cache set to be large. 127 128* Connection caching breaks if you pass the port number as an argument. 129 130 If you have a definition such as: 131 132 Mport, P=[IPC], F=kmDFMuX, S=11/31, R=21, 133 M=2100000, T=DNS/RFC822/SMTP, 134 A=IPC [127.0.0.1] $h 135 136 (i.e., where $h is the port number instead of the host name) the 137 connection caching code will break because it won't notice that 138 two messages addressed to different ports should use different 139 connections. 140 141* ESMTP SIZE underestimates the size of a message 142 143 Sendmail makes no allowance for headers that it adds, nor does it 144 account for the SMTP on-the-wire \r\n expansion. It probably doesn't 145 allow for 8->7 bit MIME conversions either. 146 147* Client ignores SIZE parameter. 148 149 When sendmail acts as client and the server specifies a limit 150 for the mail size, sendmail will ignore this and try to send the 151 mail anyway. The server will usually reject the MAIL command 152 which specifies the size of the message and hence this problem 153 is not significant. 154 155* Paths to programs being executed and the mode of program files are 156 not checked. Essentially, the RunProgramInUnsafeDirPath and 157 RunWritableProgram bits in the DontBlameSendmail option are always 158 set. This is not a problem if your system is well managed (that is, 159 if binaries and system directories are mode 755 instead of something 160 foolish like 777). 161 162* 8-bit data in GECOS field 163 164 If the GECOS (personal name) information in the passwd file contains 165 8-bit characters, those characters can be included in the message 166 header, which can cause problems when sending SMTP to hosts that 167 only accept 7-bit characters. 168 169* 8->7 bit MIME conversion 170 171 When sendmail is doing 8->7 bit MIME conversions, and the message 172 contains certain MIME body types that cannot be converted to 7-bit, 173 sendmail will strip the message to 7-bit. 174 175* 7->8 bit MIME conversion 176 177 If a message that is encoded as 7-bit MIME is converted to 8-bit and 178 that message when decoded is illegal (e.g., because of long lines or 179 illegal characters), sendmail can produce an illegal message. 180 181* MIME encoded full name phrases in the From: header 182 183 If a full name phrase includes characters from MustQuoteChars, sendmail 184 will quote the entire full name phrase. If MustQuoteChars includes 185 characters which are not special characters according to STD 11 (RFC 186 822), this quotation can interfere with MIME encoded full name phrases. 187 By default, sendmail includes the single quote character (') in 188 MustQuoteChars even though it is not listed as a special character in 189 STD 11. 190 191* bestmx map with -z flag truncates the list of MX hosts 192 193 A bestmx map configured with the -z flag will truncate the list 194 of MX hosts. This prevents creation of strings which are too 195 long for ruleset parsing. This can have an adverse effect on the 196 relay_based_on_MX feature. 197 198* Saving to ~sender/dead.letter fails if su'ed to root 199 200 If ErrorMode is set to print and an error in sending mail occurs, 201 the normal action is to print a message to the screen and append 202 the message to a dead.letter file in the sender's home directory. 203 In the case where the sender is using su to act as root, the file 204 safety checks prevent sendmail from saving the dead.letter file 205 because the sender's uid and the current real uid do not match. 206 207* Berkeley DB 2.X race condition with fcntl() locking 208 209 There is a race condition for Berkeley DB 2.X databases on 210 operating systems which use fcntl() style locking, such as 211 Solaris. Sendmail locks the map before calling db_open() to 212 prevent others from modifying the map while it is being opened. 213 Unfortunately, Berkeley DB opens the map, closes it, and then 214 reopens it. fcntl() locking drops the lock when any file 215 descriptor pointing to the file is closed, even if it is a 216 different file descriptor than the one used to initially lock 217 the file. As a result there is a possibility that entries in a 218 map might not be found during a map rebuild. As a workaround, 219 you can use makemap to build a map with a new name and then 220 "mv" the new db file to replace the old one. 221 222 Sleepycat Software has added code to avoid this race condition to 223 Berkeley DB versions after 2.7.5. 224 225* File open timeouts not available on hard mounted NFS file systems 226 227 Since SIGALRM does not interrupt an RPC call for hard mounted 228 NFS file systems, it is impossible to implement a timeout on a file 229 open operation. Therefore, while the NFS server is not responding, 230 attempts to open a file on that server will hang. Systems with 231 local mail delivery and NFS hard mounted home directories should be 232 avoided, as attempts to open the forward files could hang. 233 234* Race condition for delivery to set-user-ID files 235 236 Sendmail will deliver to a fail if the file is owned by the DefaultUser 237 or has the set-user-ID bit set. Unfortunately, some systems clear that bit 238 when a file is modified. Sendmail compensates by resetting the file mode 239 back to it's original settings. Unfortunately, there's still a 240 permission failure race as sendmail checks the permissions before locking 241 the file. This is unavoidable as sendmail must verify the file is safe 242 to open before opening it. A file can not be locked until it is open. 243 244* MAIL_HUB always takes precedence over LOCAL_RELAY 245 246 Despite the information in the documentation, MAIL_HUB ($H) will always 247 be used if set instead of LOCAL_RELAY ($R). This will be fixed in a 248 future version. 249 250$Revision: 8.57 $, Last updated $Date: 2004/12/02 23:39:01 $ 251