|
33e6c402
|
2019-11-28T15:26:36
|
|
patch_parse: fix out-of-bounds reads caused by integer underflow
The patch format for binary files is a simple Base85 encoding with a
length byte as prefix that encodes the current line's length. For each
line, we thus check whether the line's actual length matches its
expected length in order to not faultily apply a truncated patch. This
also acts as a check to verify that we're not reading outside of the
line's string:
if (encoded_len > ctx->parse_ctx.line_len - 1) {
error = git_parse_err(...);
goto done;
}
There is the possibility for an integer underflow, though. Given a line
with a single prefix byte, only, `line_len` will be zero when reaching
this check. As a result, subtracting one from that will result in an
integer underflow, causing us to assume that there's a wealth of bytes
available later on. Naturally, this may result in an out-of-bounds read.
Fix the issue by checking both `encoded_len` and `line_len` for a
non-zero value. The binary format doesn't make use of zero-length lines
anyway, so we need to know that there are both encoded bytes and
remaining characters available at all.
This patch also adds a test that works based on the last error message.
Checking error messages is usually too tightly coupled, but in fact
parsing the patch failed even before the change. Thus the only
possibility is to use e.g. Valgrind, but that'd result in us not
catching issues when run without Valgrind. As a result, using the error
message is considered a viable tradeoff as we know that we didn't start
decoding Base85 in the first place.
|
|
|
de7659cc
|
2019-11-10T18:44:56
|
|
patch_parse: use paths from "---"/"+++" lines for binary patches
For some patches, it is not possible to derive the old and new file
paths from the patch header's first line, most importantly when they
contain spaces. In such a case, we derive both paths from the "---" and
"+++" lines, which allow for non-ambiguous parsing. We fail to use these
paths when parsing binary patches without data, though, as we always
expect the header paths to be filled in.
Fix this by using the "---"/"+++" paths by default and only fall back to
header paths if they aren't set. If neither of those paths are set, we
just return an error. Add two tests to verify this behaviour, one of
which would have previously caused a segfault.
|
|
|
de543e29
|
2019-11-05T22:44:27
|
|
patch_parse: fix segfault when header path contains whitespace only
When parsing header paths from a patch, we reject any patches with empty
paths as malformed patches. We perform the check whether a path is empty
before sanitizing it, though, which may lead to a path becoming empty
after the check, e.g. if we have trimmed whitespace. This may lead to a
segfault later when any part of our patching logic actually references
such a path, which may then be a `NULL` pointer.
Fix the issue by performing the check after sanitizing. Add tests to
catch the issue as they would have produced a segfault previosuly.
|
|
|
37141ff7
|
2019-10-21T18:56:59
|
|
patch_parse: detect overflow when calculating old/new line position
When the patch contains lines close to INT_MAX, then it may happen that
we end up with an integer overflow when calculating the line of the
current diff hunk. Reject such patches as unreasonable to avoid the
integer overflow.
As the calculation is performed on integers, we introduce two new
helpers `git__add_int_overflow` and `git__sub_int_overflow` that perform
the integer overflow check in a generic way.
|
|
|
468e3ddc
|
2019-10-19T16:48:11
|
|
patch_parse: fix out-of-bounds read with No-NL lines
We've got two locations where we copy lines into the patch. The first
one is when copying normal " ", "-" or "+" lines, while the second
location gets executed when we copy "\ No newline at end of file" lines.
While the first one correctly uses `git__strndup` to copy only until the
newline, the other one doesn't. Thus, if the line occurs at the end of
the patch and if there is no terminating NUL character, then it may
result in an out-of-bounds read.
Fix the issue by using `git__strndup`, as was already done in the other
location. Furthermore, add allocation checks to both locations to detect
out-of-memory situations.
|
|
|
6c6c15e9
|
2019-10-19T15:52:35
|
|
patch_parse: reject empty path names
When parsing patch headers, we currently accept empty path names just
fine, e.g. a line "--- \n" would be parsed as the empty filename. This
is not a valid patch format and may cause `NULL` pointer accesses at a
later place as `git_buf_detach` will return `NULL` in that case.
Reject such patches as malformed with a nice error message.
|
|
|
223e7e43
|
2019-10-19T15:42:54
|
|
patch_parse: reject patches with multiple old/new paths
It's currently possible to have patches with multiple old path name
headers. As we didn't check for this case, this resulted in a memory
leak when overwriting the old old path with the new old path because we
simply discarded the old pointer.
Instead of fixing this by free'ing the old pointer, we should reject
such patches altogether. It doesn't make any sense for the "---" or
"+++" markers to occur multiple times within a patch n the first place.
This also implicitly fixes the memory leak.
|
|
fd7a384b
|
2019-07-20T11:24:37
|
|
Merge pull request #5159 from pks-t/pks/patch-parse-old-missing-nl
patch_parse: handle missing newline indicator in old file
|
|
b0893282
|
2019-07-11T12:12:04
|
|
patch_parse: ensure valid patch output with EOFNL
|
|
|
3f855fe8
|
2019-07-05T11:06:33
|
|
patch_parse: handle missing newline indicator in old file
When either the old or new file contents have no newline at the end of
the file, then git-diff(1) will print out a "\ No newline at end of
file" indicator. While we do correctly handle this in the case where the
new file has this indcator, we fail to parse patches where the old file
is missing a newline at EOF.
Fix this bug by handling and missing newline indicators in the old file.
Add tests to verify that we can parse such files.
|
|
|
dedf70ad
|
2019-07-05T09:35:43
|
|
patch_parse: do not depend on parsed buffer's lifetime
When parsing a patch from a buffer, we let the patch lines point into
the original buffer. While this is efficient use of resources, this also
ties the lifetime of the parsed patch to the parsed buffer. As this
behaviour is not documented anywhere in our API it is very surprising to
its users.
Untie the lifetime by duplicating the lines into the parsed patch. Add a
test that verifies that lifetimes are indeed independent of each other.
|
|
|
80226b5f
|
2017-09-22T13:39:05
|
|
patch_parse: allow parsing ambiguous patch headers
The git patch format allows for having unquoted paths with whitespaces
inside. This format becomes ambiguous to parse, e.g. in the following
example:
diff --git a/file b/with spaces.txt b/file b/with spaces.txt
While we cannot parse this in a correct way, we can instead use the
"---" and "+++" lines to retrieve the file names, as the path is not
followed by anything here but spans the complete remaining line. Because
of this, we can simply bail outwhen parsing the "diff --git" header here
without an actual error and then proceed to just take the paths from the
other headers.
|
|
94e488a0
|
2016-04-24T16:14:25
|
|
patch: differentiate not found and invalid patches
|
|
|
17572f67
|
2016-04-21T00:04:14
|
|
git_patch_parse_ctx: refcount the context
|
|
|
440e3bae
|
2015-11-21T12:27:03
|
|
patch: `git_patch_from_patchfile` -> `git_patch_from_buffer`
|
|
82175084
|
2015-09-23T13:40:12
|
|
Introduce git_patch_options, handle prefixes
Handle prefixes (in terms of number of path components) for patch
parsing.
|
|
|
42b34428
|
2015-09-22T18:54:10
|
|
patch_parse: ensure we can parse a patch
|