Such upstreams cause CPU hog later in the code as number of peers isn't
expected to be 0. Currently this may happen either if there are only backup
servers defined in an upstream block, or if server with ipv6 address used
in an upstream block.
Note that "ctxt->loadsubset = 1" previously used isn't really correct as
ctxt->loadsubset is a bitfield now. The use of xmlCtxtUseOptions() with
XML_PARSE_DTDLOAD is believed to be a better way to do the same thing.
Patch by Laurence Rowe.
POSIX doesn't require it to be defined, and Debian GNU/Hurd doesn't define
it. Note that if there is no MAX_PATH defined we have to use realpath()
with NULL argument and free() the result.
The problem was introduced in 0.7.44 (r2589) during conversion to complex
values. Previously string.len included space for terminating NUL, but
with complex values it doesn't.
The bug in question is likely already fixed (though unfortunately we have
no information available as Apple's bugtracker isn't open), and the
workaround seems to be too pessimistic for modern versions of Safari
as well as other webkit-based browsers pretending to be Safari.
- Removed "hash" element from ngx_http_header_val_t which was always 1.
- Replaced NGX_HTTP_EXPIRES_* with ngx_http_expires_t enum type.
- Added prototype for ngx_http_add_header()
- Simplified ngx_http_set_last_modified().
This resulted in a disclosure of previously freed memory if upstream
server returned specially crafted response, potentially exposing
sensitive information.
Reported by Matthew Daley.
Embedded perl module assumes there is a space for terminating NUL character,
make sure to provide it in all situations by allocating one extra byte for
value buffer. Default ssi_value_length is reduced accordingly to
preserve 256 byte allocations.
While here, fixed another one byte value buffer overrun possible in
ssi_quoted_symbol_state.
Reported by Matthew Daley.
It wasn't enforced for a long time, and there are reports that people
use up to 100 simultaneous subrequests now. As this is a safety limit
to prevent loops, it's raised accordingly.
Previous code incorrectly assumed that nodes with identical keys are linked
together. This might not be true after tree rebalance.
Patch by Lanshun Zhou.
To completely disable symlinks (disable_symlinks on)
we use openat(O_NOFOLLOW) for each path component
to avoid races.
To allow symlinks with the same owner (disable_symlinks if_not_owner),
use openat() (followed by fstat()) and fstatat(AT_SYMLINK_NOFOLLOW),
and then compare uids between fstat() and fstatat().
As there is a race between openat() and fstatat() we don't
know if openat() in fact opened symlink or not. Therefore,
we have to compare uids even if fstatat() reports the opened
component isn't a symlink (as we don't know whether it was
symlink during openat() or not).
Default value is off, i.e. symlinks are allowed.
Nuke NGX_PARSE_LARGE_TIME, it's not used since 0.6.30. The only error
ngx_parse_time() can currently return is NGX_ERROR, check it explicitly
and make sure to cast it to appropriate type (either time_t or ngx_msec_t)
to avoid signedness warnings on platforms with unsigned time_t (notably QNX).
Now redirects to named locations are counted against normal uri changes
limit, and post_action respects this limit as well. As a result at least
the following (bad) configurations no longer trigger infinite cycles:
1. Post action which recursively triggers post action:
location / {
post_action /index.html;
}
2. Post action pointing to nonexistent named location:
location / {
post_action @nonexistent;
}
3. Recursive error page for 500 (Internal Server Error) pointing to
a nonexistent named location:
location / {
recursive_error_pages on;
error_page 500 @nonexistent;
return 500;
}
Without the protection, subrequest loop results in r->count overflow and
SIGSEGV. Protection was broken in 0.7.25.
Note that this also limits number of parallel subrequests. This
wasn't exactly the case before 0.7.25 as local subrequests were
completed directly.
See here for details:
http://nginx.org/pipermail/nginx-ru/2010-February/032184.html
Variables with the "not_found" flag set follow the same rules as ones with
the "valid" flag set. Make sure ngx_http_get_flushed_variable() will flush
non-cacheable variables with the "not_found" flag set.
This fixes at least one known problem with $args not available in a subrequest
(with args) when there were no args in the main request and $args variable was
queried in the main request (reported by Laurence Rowe aka elro on irc).
Also this eliminates unneeded call to ngx_http_get_indexed_variable() in
cacheable case (as it will return cached value anyway).
Temporary files might not be removed if the "proxy_store" or "fastcgi_store"
directives were used for subrequests (e.g. ssi includes) and client closed
connection prematurely.
Non-active subrequests are finalized out of the control of the upstream
module when client closes a connection. As a result, the code to remove
unfinished temporary files in ngx_http_upstream_process_request() wasn't
executed.
Fix is to move relevant code into ngx_http_upstream_finalize_request() which
is called in all cases, either directly or via the cleanup handler.
Empty flush buffers are legitimate and may happen e.g. due to $r->flush()
calls in embedded perl. If there are no data buffered in zlib, deflate()
will return Z_BUF_ERROR (i.e. no progress possible) without adding anything
to output. Don't treat Z_BUF_ERROR as fatal and correctly send empty flush
buffer if we have no data in output at all.
See this thread for details:
http://mailman.nginx.org/pipermail/nginx/2010-November/023693.html
