diff options
| -rw-r--r-- | doc/doc-txt/ChangeLog | 11 | ||||
| -rw-r--r-- | src/src/log.c | 19 |
2 files changed, 23 insertions, 7 deletions
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog index 18e8d1ff8..4cb08c1dc 100644 --- a/doc/doc-txt/ChangeLog +++ b/doc/doc-txt/ChangeLog @@ -1,4 +1,4 @@ -$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.104 2005/03/29 14:53:09 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.105 2005/03/29 15:19:25 ph10 Exp $ Change log file for Exim from version 4.21 ------------------------------------------- @@ -99,6 +99,15 @@ PH/17 The API for radiusclient changed at release 0.4.0. Unfortunately, the PH/18 Installed Lars Mainka's patch for the support of CRL collections in files or directories, for OpenSSL. +PH/19 When an Exim process that is running as root has to create an Exim log + file, it does so in a subprocess that runs as exim:exim so as to get the + ownership right at creation (otherwise, other Exim processes might see + the file with the wrong ownership). There was no test for failure of this + fork() call, which would lead to the process getting stuck as it waited + for a non-existent subprocess. Forks do occasionally fail when resources + run out. I reviewed all the other calls to fork(); they all seem to check + for failure. + A note about Exim versions 4.44 and 4.50 ---------------------------------------- diff --git a/src/src/log.c b/src/src/log.c index 0d8b3d0d6..d2ef9e518 100644 --- a/src/src/log.c +++ b/src/src/log.c @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/log.c,v 1.2 2005/01/04 10:00:42 ph10 Exp $ */ +/* $Cambridge: exim/src/src/log.c,v 1.3 2005/03/29 15:19:25 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -321,8 +321,9 @@ if (*fd >= 0) /* Open was not successful: try creating the file. If this is a root process, we must do the creating in a subprocess set to exim:exim in order to ensure that the file is created with the right ownership. Otherwise, there can be a -race if an exim process is trying to write to the log at the same time. The use -of SIGUSR1 by the exiwhat utility can provoke a lot of simultaneous writing. */ +race if another Exim process is trying to write to the log at the same time. +The use of SIGUSR1 by the exiwhat utility can provoke a lot of simultaneous +writing. */ euid = geteuid(); @@ -350,10 +351,16 @@ else if (euid == root_uid) _exit((create_log(buffer) < 0)? 1 : 0); } - /* Wait for the subprocess. If it succeeded retry the open. */ + /* If we created a subprocess, wait for it. If it succeeded retry the open. */ - while (waitpid(pid, &status, 0) != pid); - if (status == 0) *fd = Uopen(buffer, O_APPEND|O_WRONLY, LOG_MODE); + if (pid > 0) + { + while (waitpid(pid, &status, 0) != pid); + if (status == 0) *fd = Uopen(buffer, O_APPEND|O_WRONLY, LOG_MODE); + } + + /* If we failed to create a subprocess, we are in a bad way. We fall through + with *fd still < 0, and errno set, letting the code below handle the error. */ } /* If we now have an open file, set the close-on-exec flag and return. */ |