kmx git

Commit	Date	Message
4209a512	2018-11-14T12:04:42	strntol: fix out-of-bounds reads when parsing numbers with leading sign When parsing a number, we accept a leading plus or minus sign to return a positive or negative number. When the parsed string has such a leading sign, we set up a flag indicating that the number is negative and advance the pointer to the next character in that string. This misses updating the number of bytes in the string, though, which is why the parser may later on do an out-of-bounds read. Fix the issue by correctly updating both the pointer and the number of remaining bytes. Furthermore, we need to check whether we actually have any bytes left after having advanced the pointer, as otherwise the auto-detection of the base may do an out-of-bonuds access. Add a test that detects the out-of-bound read. Note that this is not actually security critical. While there are a lot of places where the function is called, all of these places are guarded or irrelevant: - commit list: this operates on objects from the ODB, which are always NUL terminated any may thus not trigger the off-by-one OOB read. - config: the configuration is NUL terminated. - curl stream: user input is being parsed that is always NUL terminated - index: the index is read via `git_futils_readbuffer`, which always NUL terminates it. - loose objects: used to parse the length from the object's header. As we check previously that the buffer contains a NUL byte, this is safe. - rebase: this parses numbers from the rebase instruction sheet. As the rebase code uses `git_futils_readbuffer`, the buffer is always NUL terminated. - revparse: this parses a user provided buffer that is NUL terminated. - signature: this parser the header information of objects. As objects read from the ODB are always NUL terminated, this is a non-issue. The constructor `git_signature_from_buffer` does not accept a length parameter for the buffer, so the buffer needs to be NUL terminated, as well. - smart transport: the buffer that is parsed is NUL terminated - tree cache: this parses the tree cache from the index extension. The index itself is read via `git_futils_readbuffer`, which always NUL terminates it. - winhttp transport: user input is being parsed that is always NUL terminated
50d09407	2018-10-29T18:05:27	strntol: fix detection and skipping of base prefixes The `git__strntol` family of functions has the ability to auto-detect a number's base if the string has either the common '0x' prefix for hexadecimal numbers or '0' prefix for octal numbers. The detection of such prefixes and following handling has two major issues though that are being fixed in one go now. - We do not do any bounds checking previous to verifying the '0x' base. While we do verify that there is at least one digit available previously, we fail to verify that there are two digits available and thus may do an out-of-bounds read when parsing this two-character-prefix. - When skipping the prefix of such numbers, we only update the pointer length without also updating the number of remaining bytes. Thus if we try to parse a number '0x1' of total length 3, we will first skip the first two bytes and then try to read 3 bytes starting at '1'. Fix both issues by disentangling the logic. Instead of doing the detection and skipping of such prefixes in one go, we will now first try to detect the base while also honoring how many bytes are left. Only if we have a valid base that is either 8 or 16 and have one of the known prefixes, we will now advance the pointer and update the remaining bytes in one step. Add some tests that verify that no out-of-bounds parsing happens and that autodetection works as advertised.
41863a00	2018-10-29T17:19:58	strntol: fix out-of-bounds read when skipping leading spaces The `git__strntol` family of functions accepts leading spaces and will simply skip them. The skipping will not honor the provided buffer's length, though, which may lead it to read outside of the provided buffer's bounds if it is not a simple NUL-terminated string. Furthermore, if leading space is trimmed, the function will further advance the pointer but not update the number of remaining bytes, which may also lead to out-of-bounds reads. Fix the issue by properly paying attention to the buffer length and updating it when stripping leading whitespace characters. Add a test that verifies that we won't read past the provided buffer length.
ea19efc1	2018-10-18T15:08:56	util: fix out of bounds read in error message When an integer that is parsed with `git__strntol32` is too big to fit into an int32, we will generate an error message that includes the actual string that failed to parse. This does not acknowledge the fact that the string may either not be NUL terminated or alternative include additional characters after the number that is to be parsed. We may thus end up printing characters into the buffer that aren't the number or, worse, read out of bounds. Fix the issue by utilizing the `endptr` that was set by `git__strntol64`. This pointer is guaranteed to be set to the first character following the number, and we can thus use it to compute the width of the number that shall be printed. Create a test to verify that we correctly truncate the number.
39087ab8	2018-10-18T12:11:33	tests: core::strtol: test for some more edge-cases Some edge cases were currently completely untested, e.g. parsing numbers greater than INT64_{MIN,MAX}, truncating buffers by length and invalid characters. Add tests to verify that the system under test performs as expected.
8d7fa88a	2018-10-18T12:04:07	util: remove `git__strtol32` The function `git__strtol32` can easily be misused when untrusted data is passed to it that may not have been sanitized with trailing `NUL` bytes. As all usages of this function have now been removed, we can remove this function altogether to avoid future misuse of it.
68deb2cc	2018-10-18T11:37:10	util: remove unsafe `git__strtol64` function The function `git__strtol64` does not take a maximum buffer length as parameter. This has led to some unsafe usages of this function, and as such we may consider it as being unsafe to use. As we have now eradicated all usages of this function, let's remove it completely to avoid future misuse.
70b9b841	2016-06-28T20:19:52	Fixed bug while parsing INT64_MIN
17820381	2013-11-14T14:05:52	Rename tests-clar to tests

4209a512

2018-11-14T12:04:42

strntol: fix out-of-bounds reads when parsing numbers with leading sign When parsing a number, we accept a leading plus or minus sign to return a positive or negative number. When the parsed string has such a leading sign, we set up a flag indicating that the number is negative and advance the pointer to the next character in that string. This misses updating the number of bytes in the string, though, which is why the parser may later on do an out-of-bounds read. Fix the issue by correctly updating both the pointer and the number of remaining bytes. Furthermore, we need to check whether we actually have any bytes left after having advanced the pointer, as otherwise the auto-detection of the base may do an out-of-bonuds access. Add a test that detects the out-of-bound read. Note that this is not actually security critical. While there are a lot of places where the function is called, all of these places are guarded or irrelevant: - commit list: this operates on objects from the ODB, which are always NUL terminated any may thus not trigger the off-by-one OOB read. - config: the configuration is NUL terminated. - curl stream: user input is being parsed that is always NUL terminated - index: the index is read via `git_futils_readbuffer`, which always NUL terminates it. - loose objects: used to parse the length from the object's header. As we check previously that the buffer contains a NUL byte, this is safe. - rebase: this parses numbers from the rebase instruction sheet. As the rebase code uses `git_futils_readbuffer`, the buffer is always NUL terminated. - revparse: this parses a user provided buffer that is NUL terminated. - signature: this parser the header information of objects. As objects read from the ODB are always NUL terminated, this is a non-issue. The constructor `git_signature_from_buffer` does not accept a length parameter for the buffer, so the buffer needs to be NUL terminated, as well. - smart transport: the buffer that is parsed is NUL terminated - tree cache: this parses the tree cache from the index extension. The index itself is read via `git_futils_readbuffer`, which always NUL terminates it. - winhttp transport: user input is being parsed that is always NUL terminated

50d09407

2018-10-29T18:05:27

strntol: fix detection and skipping of base prefixes The `git__strntol` family of functions has the ability to auto-detect a number's base if the string has either the common '0x' prefix for hexadecimal numbers or '0' prefix for octal numbers. The detection of such prefixes and following handling has two major issues though that are being fixed in one go now. - We do not do any bounds checking previous to verifying the '0x' base. While we do verify that there is at least one digit available previously, we fail to verify that there are two digits available and thus may do an out-of-bounds read when parsing this two-character-prefix. - When skipping the prefix of such numbers, we only update the pointer length without also updating the number of remaining bytes. Thus if we try to parse a number '0x1' of total length 3, we will first skip the first two bytes and then try to read 3 bytes starting at '1'. Fix both issues by disentangling the logic. Instead of doing the detection and skipping of such prefixes in one go, we will now first try to detect the base while also honoring how many bytes are left. Only if we have a valid base that is either 8 or 16 and have one of the known prefixes, we will now advance the pointer and update the remaining bytes in one step. Add some tests that verify that no out-of-bounds parsing happens and that autodetection works as advertised.

41863a00

2018-10-29T17:19:58

strntol: fix out-of-bounds read when skipping leading spaces The `git__strntol` family of functions accepts leading spaces and will simply skip them. The skipping will not honor the provided buffer's length, though, which may lead it to read outside of the provided buffer's bounds if it is not a simple NUL-terminated string. Furthermore, if leading space is trimmed, the function will further advance the pointer but not update the number of remaining bytes, which may also lead to out-of-bounds reads. Fix the issue by properly paying attention to the buffer length and updating it when stripping leading whitespace characters. Add a test that verifies that we won't read past the provided buffer length.

ea19efc1

2018-10-18T15:08:56

util: fix out of bounds read in error message When an integer that is parsed with `git__strntol32` is too big to fit into an int32, we will generate an error message that includes the actual string that failed to parse. This does not acknowledge the fact that the string may either not be NUL terminated or alternative include additional characters after the number that is to be parsed. We may thus end up printing characters into the buffer that aren't the number or, worse, read out of bounds. Fix the issue by utilizing the `endptr` that was set by `git__strntol64`. This pointer is guaranteed to be set to the first character following the number, and we can thus use it to compute the width of the number that shall be printed. Create a test to verify that we correctly truncate the number.

39087ab8

2018-10-18T12:11:33

tests: core::strtol: test for some more edge-cases Some edge cases were currently completely untested, e.g. parsing numbers greater than INT64_{MIN,MAX}, truncating buffers by length and invalid characters. Add tests to verify that the system under test performs as expected.

8d7fa88a

2018-10-18T12:04:07

util: remove `git__strtol32` The function `git__strtol32` can easily be misused when untrusted data is passed to it that may not have been sanitized with trailing `NUL` bytes. As all usages of this function have now been removed, we can remove this function altogether to avoid future misuse of it.

68deb2cc

2018-10-18T11:37:10

util: remove unsafe `git__strtol64` function The function `git__strtol64` does not take a maximum buffer length as parameter. This has led to some unsafe usages of this function, and as such we may consider it as being unsafe to use. As we have now eradicated all usages of this function, let's remove it completely to avoid future misuse.

70b9b841

2016-06-28T20:19:52

Fixed bug while parsing INT64_MIN

17820381

2013-11-14T14:05:52

Rename tests-clar to tests

thodg/libgit2/tests/core/strtol.c

tests/core/strtol.c

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