Mercurial > hg > nginx-quic
view auto/summary @ 8460:3974f4e56a4e
Mail: fixed s->arg_start clearing on invalid IMAP commands.
Previously, s->arg_start was left intact after invalid IMAP commands,
and this might result in an argument incorrectly added to the following
command. Similarly, s->backslash was left intact as well, leading
to unneeded backslash removal.
For example (LFs from the client are explicitly shown as "<LF>"):
S: * OK IMAP4 ready
C: a01 login "\<LF>
S: a01 BAD invalid command
C: a0000000000\2 authenticate <LF>
S: a00000000002 aBAD invalid command
The backslash followed by LF generates invalid command with s->arg_start
and s->backslash set, the following command incorrectly treats anything
from the old s->arg_start to the space after the command as an argument,
and removes the backslash from the tag. If there is no space, s->arg_end
will be NULL.
Both things seem to be harmless though. In particular:
- This can be used to provide an incorrect argument to a command without
arguments. The only command which seems to look at the single argument
is AUTHENTICATE, and it checks the argument length before trying to
access it.
- Backslash removal uses the "end" pointer, and stops due to "src < end"
condition instead of scanning all the process memory if s->arg_end is
NULL (and arg[0].len is huge).
- There should be no backslashes in unquoted strings.
An obvious fix is to clear s->arg_start and s->backslash on invalid commands,
similarly to how it is done in POP3 parsing (added in 810:e3aa8f305d21) and
SMTP parsing.
This, however, makes it clear that s->arg_start handling in the "done"
label is wrong: s->arg_start cannot be legitimately set there, as it
is expected to be cleared in all possible cases when the "done" label is
reached. The relevant code is dead and will be removed by the following
change.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Wed, 19 May 2021 03:13:20 +0300 |
| parents | 9eefb38f0005 |
| children | 0b5f12d5c531 |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. echo echo "Configuration summary" if [ $USE_THREADS = YES ]; then echo " + using threads" fi if [ $USE_PCRE = DISABLED ]; then echo " + PCRE library is disabled" else case $PCRE in YES) echo " + using system PCRE library" ;; NONE) echo " + PCRE library is not used" ;; *) echo " + using PCRE library: $PCRE" ;; esac fi case $OPENSSL in YES) echo " + using system OpenSSL library" ;; NONE) echo " + OpenSSL library is not used" ;; *) echo " + using OpenSSL library: $OPENSSL" ;; esac case $ZLIB in YES) echo " + using system zlib library" ;; NONE) echo " + zlib library is not used" ;; *) echo " + using zlib library: $ZLIB" ;; esac case $NGX_LIBATOMIC in YES) echo " + using system libatomic_ops library" ;; NO) ;; # not used *) echo " + using libatomic_ops library: $NGX_LIBATOMIC" ;; esac echo cat << END nginx path prefix: "$NGX_PREFIX" nginx binary file: "$NGX_SBIN_PATH" nginx modules path: "$NGX_MODULES_PATH" nginx configuration prefix: "$NGX_CONF_PREFIX" nginx configuration file: "$NGX_CONF_PATH" nginx pid file: "$NGX_PID_PATH" END if test -n "$NGX_ERROR_LOG_PATH"; then echo " nginx error log file: \"$NGX_ERROR_LOG_PATH\"" else echo " nginx logs errors to stderr" fi cat << END nginx http access log file: "$NGX_HTTP_LOG_PATH" nginx http client request body temporary files: "$NGX_HTTP_CLIENT_TEMP_PATH" END if [ $HTTP_PROXY = YES ]; then echo " nginx http proxy temporary files: \"$NGX_HTTP_PROXY_TEMP_PATH\"" fi if [ $HTTP_FASTCGI = YES ]; then echo " nginx http fastcgi temporary files: \"$NGX_HTTP_FASTCGI_TEMP_PATH\"" fi if [ $HTTP_UWSGI = YES ]; then echo " nginx http uwsgi temporary files: \"$NGX_HTTP_UWSGI_TEMP_PATH\"" fi if [ $HTTP_SCGI = YES ]; then echo " nginx http scgi temporary files: \"$NGX_HTTP_SCGI_TEMP_PATH\"" fi echo "$NGX_POST_CONF_MSG"