Don't use a separate function to handle "complex" attributes. Validate
UTF-8 byte sequences without decoding. This should improve performance
considerably when parsing multi-byte UTF-8 sequences.
Use a string buffer to avoid unnecessary allocations and copying when
expanding entities.
Normalize attribute values in a single pass while expanding entities.
Be more lenient in recovery mode.
If no entity substitution was requested, validate entities without
expanding. Fixes#596.
Also fixes#655.
This allows to report the reason why opening a file failed to the parser
context and improve error messages. Now we can also remove the stat call
before opening a file.
Fix places where malloc failures aren't reported.
Introduce new API function xmlAddEntity that returns separate error
codes.
Don't invoke global error handler for low-level errors which should be
handled by higher layers.
Invalid redelcaration warnings will be fixed later.
Partial revert of cb927e85 fixing CRLFs not incrementing the line
number.
This requires to rework xmlParseQNameHashed. The original implementation
prompted the change to xmlCurrentChar which really shouldn't modify the
'cur' pointer as side effect. But the NEXTL macro relies on this
behavior.
Ultimately, we should reintroduce the change to xmlCurrentChar and fix
the NEXTL macro. This will lead to single CRs incrementing the line
number as well which seems more consistent.
Fixes#628.
When decoding input data, check whether the "raw" buffer is empty after
parsing the document. Otherwise, the input ends with a truncated
multi-byte sequence which shouldn't be silently ignored.
If we try to continue parsing after an error in the internal or external
subset, entity expansion accounting gets more complicated. Simply halt
the parser.
Found with libFuzzer.
Don't set the "checked" flag when checking entities in default attribute
values. These entities could reference other entities which weren't
defined yet, so the check isn't reliable.
This fixes a short-lived regression which could lead to a call stack
overflow later in xmlStringGetNodeList.
Remove inaccurate xmlParseCheckTransition check.
Remove non-incremental xmlParseGetLasts check.
Add functions that check for several boundary constructs more
accurately, keeping track of progress in ctxt->checkIndex.
Fixes#439.
This is another attempt at fixing parser progress checks. Instead of
relying on in->consumed, which could overflow, change some DTD parser
functions to make guaranteed progress on certain byte sequences.
Downgrade the error message to a warning since the error was ignored,
anyway. Also print the name of redeclared entity. For a proper fix that
also shows filename and line number of the invalid redeclaration, we'd
have to
- pass the parser context to the entity functions somehow, or
- make these functions return distinct error codes.
Partial fix for #308.
Readd the XML_ERR_TAG_NOT_FINISHED error on unexpected EOF which was
removed in commit 62150ed2.
This commit also introduced a regression for direct users of
xmlParseContent. Unclosed tags weren't checked.
Commit 62150ed2 introduced a small regression in the error messages for
mismatched tags. This typically only affected messages after the first
mismatch, but with custom SAX handlers all line numbers would be off.
This also fixes line numbers in the SAX push parser which were never
handled correctly.
Implement section "4.6 Predefined Entities" of the XML 1.0 spec and
check whether redeclarations of predefined entities match the original
definitions.
Note that some test cases declared
<!ENTITY lt "<">
But the XML spec clearly states that this is illegal:
> If the entities lt or amp are declared, they MUST be declared as
> internal entities whose replacement text is a character reference to
> the respective character (less-than sign or ampersand) being escaped;
> the double escaping is REQUIRED for these entities so that references
> to them produce a well-formed result.
Also fixes#217 but the connection is only tangential. The integer
overflow discovered by fuzzing was more related to the fact that various
parts of the parser disagreed on whether to prefer predefined entities
over their redeclarations. The whole situation is a mess and even
depends on legacy parser options. But now that redeclarations are
validated, it shouldn't make a difference.
As noted in the added comment, this is also one of the cases where
overly defensive checks can hide interesting logic bugs from fuzzers.
This reverts commit 79c8a6b which caused a serious regression in
streaming mode.
Also reverts part of commit 52ceced "Fix infinite loops with push
parser in recovery mode".
Fixes bug 786554.
When expanding a parameter entity in a DTD, infinite recursion could
lead to an infinite loop or memory exhaustion.
Thanks to Wei Lei for the first of many reports.
Fixes bug 759579.
Now that replacement of parameter entities goes exclusively through
xmlSkipBlankChars, we can account for the surrounding space characters
there and remove the "blanks wrapper" hack.
Pop all extra input streams before resetting the input. Otherwise,
a call to xmlPopInput could make input available again.
Also set input->end to input->cur.
Changes the test output for some error tests. Unfortunately, some
fuzzed test cases were added to the test suite without manual cleanup.
This makes it almost impossible to review the impact of later changes
on the test output.
Make sure to finish all entities in the internal subset. Nevertheless,
readd a sanity check in xmlParseStartTag2 that was lost in my previous
commit. Also add a sanity check in xmlPopInput. Popping an input
unexpectedly was the source of many recent memory bugs. The check
doesn't mitigate such issues but helps with diagnosis.
Always base entity boundary checks on the input ID, not the input
pointer. The pointer could have been reallocated to the old address.
Always throw a well-formedness error if a boundary check fails. In a
few places, a validity error was thrown.
Fix a few error codes and improve indentation.
Before, truncated UTF-8 sequences at the end of a file were treated as
EOF. Create an error message containing the offending bytes.
xmlStringCurrentChar would also print characters from the input stream,
not the string it's working on.
The code in xmlParseStartTag2 must handle the case that the input
buffer was grown and reallocated which can invalidate pointers to
attribute values. Before, this was handled by detecting changes of
the input buffer "base" pointer and, in case of a change, jumping
back to the beginning of the function and reparsing the start tag.
The major problem of this approach is that whether an input buffer is
reallocated is nondeterministic, resulting in seemingly random test
failures. See the mailing list thread "runtest mystery bug: name2.xml
error case regression test" from 2012, for example.
If a reallocation was detected, the code also made no attempts to
continue parsing in case of errors which makes a difference in
the lax "recover" mode.
Now we store the current input buffer "base" pointer for each (not
separately allocated) attribute in the namespace URI field, which isn't
used until later. After the whole start tag was parsed, the pointers
to the attribute values are reconstructed using the offset between the
new and the old input buffer. This relies on arithmetic on dangling
pointers which is technically undefined behavior. But it seems like
the easiest and most efficient fix and a similar approach is used in
xmlParserInputGrow.
This changes the error output of several tests, typically making it
more verbose because we try harder to continue parsing in case of
errors.
(Another possible solution is to check not only the "base" pointer
but the size of the input buffer as well. But this would result in
even more reparsing.)
For https://bugzilla.gnome.org/show_bug.cgi?id=759573
* parser.c:
(xmlParseElementDecl): Return early on invalid input to fix
non-minimized test case (759573-2.xml). Otherwise the parser
gets into a bad state in SKIP(3) at the end of the function.
(xmlParseConditionalSections): Halt parsing when hitting invalid
input that would otherwise caused xmlParserHandlePEReference()
to recurse unexpectedly. This fixes the minimized test case
(759573.xml).
* result/errors/759573-2.xml: Add.
* result/errors/759573-2.xml.err: Add.
* result/errors/759573-2.xml.str: Add.
* result/errors/759573.xml: Add.
* result/errors/759573.xml.err: Add.
* result/errors/759573.xml.str: Add.
* test/errors/759573-2.xml: Add.
* test/errors/759573.xml: Add.
For https://bugzilla.gnome.org/show_bug.cgi?id=759020
* parser.c:
(xmlParseStartTag2): Attribute strings are only valid if the
base does not change, so add another check where the base may
change. Make sure to set 'attvalue' to NULL after freeing it.
* result/errors/759020.xml: Added.
* result/errors/759020.xml.err: Added.
* result/errors/759020.xml.str: Added.
* test/errors/759020.xml: Added test case.
* parser.c:
(xmlParseNCNameComplex): Store start position instead of a
pointer to the name since the underlying buffer may change,
resulting in a stale pointer being used.
* result/errors/759398.xml: Added.
* result/errors/759398.xml.err: Added.
* result/errors/759398.xml.str: Added.
* test/errors/759398.xml: Added test case.
