When secure link checksum has length of 23 or 24 bytes, decoded base64 value
could occupy 17 or 18 bytes which is more than 16 bytes previously allocated
for it on stack. The buffer overflow does not have any security implications
since only one local variable was corrupted and this variable was not used in
this case.
The fix is to increase buffer size up to 18 bytes. Useless buffer size
initialization is removed as well.
This fixes at least the following cases, where no last_modified_time
(assuming caching is not enabled) resulted in incorrect behaviour:
- slice filter and If-Range requests (ticket #1357);
- If-Range requests with proxy_force_ranges;
- expires modified.
The $ssl_server_name variable used SSL_get_servername() result directly,
but this is not safe: it references a memory allocation in an SSL
session, and this memory might be freed at any time due to renegotiation.
Instead, copy the name to memory allocated from the pool.
This variable contains URL-encoded client SSL certificate. In contrast
to $ssl_client_cert, it doesn't depend on deprecated header continuation.
The NGX_ESCAPE_URI_COMPONENT variant of encoding is used, so the resulting
variable can be safely used not only in headers, but also as a request
argument.
The $ssl_client_cert variable should be considered deprecated now.
The $ssl_client_raw_cert variable will be eventually renambed back
to $ssl_client_cert.
Total length of a response with multiple ranges can be larger than a size_t
variable can hold, so type changed to off_t. Previously, an incorrect
Content-Length was returned when requesting more than 4G of ranges from
a large enough file on a 32-bit system.
An additional size_t variable introduced to calculate size of the boundary
header buffer, as off_t is not needed here and will require type casts on
win32.
Reported by Shuxin Yang,
http://mailman.nginx.org/pipermail/nginx/2017-July/054384.html.
The "fd" field should be after 3 pointers for ngx_event_ident() to use it.
This was broken by ccad84a174e0. While it does not seem to be currently used
for aio-related events, it should be a good idea to preserve the correct
layout nevertheless.
Pass NGX_FILE_OPEN to ngx_open_file() to fix "The parameter is incorrect"
error on win32 when using the ssl_session_ticket_key directive or loading
a binary geo base. On UNIX, this change is a no-op.
On Windows, a worker process does not call ngx_slab_init() from
ngx_init_zone_pool(), so ngx_slab_max_size, ngx_slab_exact_size,
and ngx_slab_exact_shift were left uninitialized.
The variable was considered non-existent in the absence of any
valid_referers directives.
Given the following config snippet,
location / {
return 200 $invalid_referer;
}
location /referer {
valid_referers server_names;
}
"location /" should work identically and independently on other
"location /referer".
The fix is to always add the $invalid_referer variable as long
as the module is compiled in, as is done by other modules.
The shared objects should generally be allocated from shared memory.
While peers->name and the data it points to allocated from cf->pool
happened to work on UNIX, it broke on Windows. On UNIX this worked
only because the shared memory zone for upstreams is re-created for
every new configuration.
But on Windows, a worker process does not inherit the address space
of the master process, so the peers->name pointed to data allocated
from cf->pool by the master process, and was invalid.
The phase is added instead of the try_files phase. Unlike the old phase, the
new one supports registering multiple handlers. The try_files implementation is
moved to a separate ngx_http_try_files_module, which now registers a precontent
phase handler.
The new request flag "preserve_body" indicates that the request body file should
not be removed by the upstream module because it may be used later by a
subrequest. The flag is set by the SSI (ticket #585), addition and slice
modules. Additionally, it is also set by the upstream module when a background
cache update subrequest is started to prevent the request body file removal
after an internal redirect. Only the main request is now allowed to remove the
file.
The http_rewrite module cannot be selected when http is disabled.
Fixed the PCRE check condition to avoid irrelevant check failure.
This is a regression from 4d874b4d82ed.
Signed-off-by: Samuel Martin <s.martin49@gmail.com>
When closing a socket with SO_REUSEPORT, Linux drops all connections waiting
in this socket's listen queue. Previously, it was believed to only result
in connection resets when reconfiguring nginx to use smaller number of worker
processes. It also results in connection resets during configuration
testing though.
Workaround is to avoid using SO_REUSEPORT when testing configuration. It
should prevent listening sockets from being created if a conflicting socket
already exists, while still preserving detection of other possible errors.
It should also cover UDP sockets.
The only downside of this approach seems to be that a configuration testing
won't be able to properly report the case when nginx was compiled with
SO_REUSEPORT, but the kernel is not able to set it. Such errors will be
reported on a real start instead.
Suffix ranges no longer allowed to set negative start values, to prevent
ranges with negative start from appearing even if total size protection
will be removed.
The overflow can be used to circumvent the restriction on total size of
ranges introduced in c2a91088b0c0 (1.1.2). Additionally, overflow
allows producing ranges with negative start (such ranges can be created
by using a suffix, "bytes=-100"; normally this results in 200 due to
the total size check). These can result in the following errors in logs:
[crit] ... pread() ... failed (22: Invalid argument)
[alert] ... sendfile() failed (22: Invalid argument)
When using cache, it can be also used to reveal cache file header.
It is believed that there are no other negative effects, at least with
standard nginx modules.
In theory, this can also result in memory disclosure and/or segmentation
faults if multiple ranges are allowed, and the response is returned in a
single in-memory buffer. This never happens with standard nginx modules
though, as well as known 3rd party modules.
Fix is to properly protect from possible overflow when incrementing size.
It is safe because re-sending still works during graceful shutdown as
long as resolving takes place (and resolve tasks set their own timeouts
that are not cancelable).
Also, the new ctx->cancelable flag can be set to make resolve task's
timeout event cancelable.
Notably, on ppc64 with 64k pagesize, slab 0 (of size 8) requires
128 64-bit elements for bitmasks. The code bogusly assumed that
one uintptr_t is enough for bitmasks plus at least one free slot.
Resolving an SRV record includes resolving its host names in subrequests.
Previously, if memory allocation failed while reporting a subrequest result
after receiving a response from a DNS server, the SRV resolve handler was
called immediately with the NGX_ERROR state. However, if the SRV record
included another copy of the resolved name, it was reported once again.
This could trigger the use-after-free memory access after SRV resolve
handler freed the resolve context by calling ngx_resolve_name_done().
Now the SRV resolve handler is called only when all its subrequests are
completed.
Previously, each configured header was represented in one of two ways,
depending on whether or not its value included any variables.
If the value didn't include any variables, then it would be represented
as as a single script that contained complete header line with HTTP/1.1
delimiters, i.e.:
"Header: value\r\n"
But if the value included any variables, then it would be represented
as a series of three scripts: first contained header name and the ": "
delimiter, second evaluated to header value, and third contained only
"\r\n", i.e.:
"Header: "
"$value"
"\r\n"
This commit changes that, so that each configured header is represented
as a series of two scripts: first contains only header name, and second
contains (or evaluates to) only header value, i.e.:
"Header"
"$value"
or
"Header"
"value"
This not only makes things more consistent, but also allows header name
and value to be accessed separately.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
As per RFC 2616 / RFC 7233, any range request to an empty file
is expected to result in 416 Range Not Satisfiable response, as
there cannot be a "byte-range-spec whose first-byte-pos is less
than the current length of the entity-body". On the other hand,
this makes use of byte-range requests inconvenient in some cases,
as reported for the slice module here:
http://mailman.nginx.org/pipermail/nginx-devel/2017-June/010177.html
This commit changes range filter to instead return 200 if the file
is empty and the range requested starts at 0.
This change reworks 13a5f4765887 to only run posted requests once,
with nothing on stack. Running posted requests with other request
functions on stack may result in use-after-free in case of errors,
similar to the one reported in #788.
To only run posted request once, a separate function was introduced
to be used as ssl handshake handler in c->ssl->handler,
ngx_http_upstream_ssl_handshake_handler(). The ngx_http_run_posted_requests()
is only called in this function, and not in ngx_http_upstream_ssl_handshake()
which may be called directly on stack.
Additionaly, ngx_http_upstream_ssl_handshake_handler() now does appropriate
debug logging of the current subrequest, similar to what is done in other
event handlers.
Previously, the upstream resolve handler always called
ngx_http_run_posted_requests() to run posted requests after processing the
resolver response. However, if the handler was called directly from the
ngx_resolve_name() function (for example, if the resolver response was cached),
running posted requests from the handler could lead to the following errors:
- If the request was scheduled for termination, it could actually be terminated
in the resolve handler. Upper stack frames could reference the freed request
object in this case.
- If a significant number of requests were posted, and for each of them the
resolve handler was called directly from the ngx_resolve_name() function,
posted requests could be run recursively and lead to stack overflow.
Now ngx_http_run_posted_requests() is only called from asynchronously invoked
resolve handlers.
