|
86852613
|
2019-12-13T12:13:05
|
|
smart_pkt: fix overflow resulting in OOB read/write of one byte
When parsing OK packets, we copy any information after the initial "ok "
prefix into the resulting packet. As newlines act as packet boundaries,
we also strip the trailing newline if there is any. We do not check
whether there is any data left after the initial "ok " prefix though,
which leads to a pointer overflow in that case as `len == 0`:
if (line[len - 1] == '\n')
--len;
This out-of-bounds read is a rather useless gadget, as we can only
deduce whether at some offset there is a newline character. In case
there accidentally is one, we overflow `len` to `SIZE_MAX` and then
write a NUL byte into an array indexed by it:
pkt->ref[len] = '\0';
Again, this doesn't seem like something that's possible to be exploited
in any meaningful way, but it may surely lead to inconsistencies or DoS.
Fix the issue by checking whether there is any trailing data after the
packet prefix.
|
|
f673e232
|
2018-12-27T13:47:34
|
|
git_error: use new names in internal APIs and usage
Move to the `git_error` name in the internal API for error-related
functions.
|
|
|
2613fbb2
|
2018-10-18T11:58:14
|
|
global: replace remaining use of `git__strtol32`
Replace remaining uses of the `git__strtol32` function. While these uses
are all safe as the strings were either sanitized or from a trusted
source, we want to remove `git__strtol32` altogether to avoid future
misuse.
|
|
|
1bc5b05c
|
2018-10-03T16:17:21
|
|
smart_pkt: do not accept callers passing in no line length
Right now, we simply ignore the `linelen` parameter of
`git_pkt_parse_line` in case the caller passed in zero. But in fact, we
never want to assume anything about the provided buffer length and
always want the caller to pass in the available number of bytes.
And in fact, checking all the callers, one can see that the funciton is
never being called in case where the buffer length is zero, and thus we
are safe to remove this check.
|
|
|
c05790a8
|
2018-08-09T11:16:15
|
|
smart_pkt: return parsed length via out-parameter
The `parse_len` function currently directly returns the parsed length of
a packet line or an error code in case there was an error. Instead,
convert this to our usual style of using the return value as error code
only and returning the actual value via an out-parameter. Thus, we can
now convert the output parameter to an unsigned type, as the size of a
packet cannot ever be negative.
While at it, we also move the check whether the input buffer is long
enough into `parse_len` itself. We don't really want to pass around
potentially non-NUL-terminated buffers to functions without also passing
along the length, as this is dangerous in the unlikely case where other
callers for that function get added. Note that we need to make sure
though to not mess with `GIT_EBUFS` error codes, as these indicate not
an error to the caller but that he needs to fetch more data.
|
|
|
0b3dfbf4
|
2018-08-09T11:13:59
|
|
smart_pkt: reorder and rename parameters of `git_pkt_parse_line`
The parameters of the `git_pkt_parse_line` function are quite confusing.
First, there is no real indicator what the `out` parameter is actually
all about, and it's not really clear what the `bufflen` parameter refers
to. Reorder and rename the parameters to make this more obvious.
|
|
|
5fabaca8
|
2018-08-09T11:04:42
|
|
smart_pkt: fix buffer overflow when parsing "unpack" packets
When checking whether an "unpack" packet returned the "ok" status or
not, we use a call to `git__prefixcmp`. In case where the passed line
isn't properly NUL terminated, though, this may overrun the line buffer.
Fix this by using `git__prefixncmp` instead.
|
|
|
b5ba7af2
|
2018-08-09T11:03:37
|
|
smart_pkt: fix "ng" parser accepting non-space character
When parsing "ng" packets, we blindly assume that the character
immediately following the "ng" prefix is a space and skip it. As the
calling function doesn't make sure that this is the case, we can thus
end up blindly accepting an invalid packet line.
Fix the issue by using `git__prefixncmp`, checking whether the line
starts with "ng ".
|
|
|
a9f1ca09
|
2018-08-09T11:01:00
|
|
smart_pkt: fix buffer overflow when parsing "ok" packets
There are two different buffer overflows present when parsing "ok"
packets. First, we never verify whether the line already ends after
"ok", but directly go ahead and also try to skip the expected space
after "ok". Second, we then go ahead and use `strchr` to scan for the
terminating newline character. But in case where the line isn't
terminated correctly, this can overflow the line buffer.
Fix the issues by using `git__prefixncmp` to check for the "ok " prefix
and only checking for a trailing '\n' instead of using `memchr`. This
also fixes the issue of us always requiring a trailing '\n'.
Reported by oss-fuzz, issue 9749:
Crash Type: Heap-buffer-overflow READ {*}
Crash Address: 0x6310000389c0
Crash State:
ok_pkt
git_pkt_parse_line
git_smart__store_refs
Sanitizer: address (ASAN)
|
|
|
bc349045
|
2018-08-09T10:38:10
|
|
smart_pkt: fix buffer overflow when parsing "ACK" packets
We are being quite lenient when parsing "ACK" packets. First, we didn't
correctly verify that we're not overrunning the provided buffer length,
which we fix here by using `git__prefixncmp` instead of
`git__prefixcmp`. Second, we do not verify that the actual contents make
any sense at all, as we simply ignore errors when parsing the ACKs OID
and any unknown status strings. This may result in a parsed packet
structure with invalid contents, which is being silently passed to the
caller. This is being fixed by performing proper input validation and
checking of return codes.
|
|
|
5edcf5d1
|
2018-08-09T10:57:06
|
|
smart_pkt: adjust style of "ref" packet parsing function
While the function parsing ref packets doesn't have any immediately
obvious buffer overflows, it's style is different to all the other
parsing functions. Instead of checking buffer length while we go, it
does a check up-front. This causes the code to seem a lot more magical
than it really is due to some magic constants. Refactor the function to
instead make use of the style of other packet parser and verify buffer
lengths as we go.
|
|
|
786426ea
|
2018-08-09T10:46:58
|
|
smart_pkt: check whether error packets are prefixed with "ERR "
In the `git_pkt_parse_line` function, we determine what kind of packet
a given packet line contains by simply checking for the prefix of that
line. Except for "ERR" packets, we always only check for the immediate
identifier without the trailing space (e.g. we check for an "ACK"
prefix, not for "ACK "). But for "ERR" packets, we do in fact include
the trailing space in our check. This is not really much of a problem at
all, but it is inconsistent with all the other packet types and thus
causes confusion when the `err_pkt` function just immediately skips the
space without checking whether it overflows the line buffer.
Adjust the check in `git_pkt_parse_line` to not include the trailing
space and instead move it into `err_pkt` for consistency.
|
|
|
40fd84cc
|
2018-08-09T10:46:26
|
|
smart_pkt: explicitly avoid integer overflows when parsing packets
When parsing data, progress or error packets, we need to copy the
contents of the rest of the current packet line into the flex-array of
the parsed packet. To keep track of this array's length, we then assign
the remaining length of the packet line to the structure. We do have a
mismatch of types here, as the structure's `len` field is a signed
integer, while the length that we are assigning has type `size_t`.
On nearly all platforms, this shouldn't pose any problems at all. The
line length can at most be 16^4, as the line's length is being encoded
by exactly four hex digits. But on a platforms with 16 bit integers,
this assignment could cause an overflow. While such platforms will
probably only exist in the embedded ecosystem, we still want to avoid
this potential overflow. Thus, we now simply change the structure's
`len` member to be of type `size_t` to avoid any integer promotion.
|
|
|
4a5804c9
|
2018-08-09T10:36:44
|
|
smart_pkt: honor line length when determining packet type
When we parse the packet type of an incoming packet line, we do not
verify that we don't overflow the provided line buffer. Fix this by
using `git__prefixncmp` instead and passing in `len`. As we have
previously already verified that `len <= linelen`, we thus won't ever
overflow the provided buffer length.
|
|
50dd7fea
|
2018-08-11T13:06:14
|
|
Fix 'invalid packet line' for ng packets containing errors
|
|
|
19bed3e2
|
2018-07-19T13:00:42
|
|
smart_pkt: fix potential OOB-read when processing ng packet
OSS-fuzz has reported a potential out-of-bounds read when processing a
"ng" smart packet:
==1==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6310000249c0 at pc 0x000000493a92 bp 0x7ffddc882cd0 sp 0x7ffddc882480
READ of size 65529 at 0x6310000249c0 thread T0
SCARINESS: 26 (multi-byte-read-heap-buffer-overflow)
#0 0x493a91 in __interceptor_strchr.part.35 /src/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc:673
#1 0x813960 in ng_pkt libgit2/src/transports/smart_pkt.c:320:14
#2 0x810f79 in git_pkt_parse_line libgit2/src/transports/smart_pkt.c:478:9
#3 0x82c3c9 in git_smart__store_refs libgit2/src/transports/smart_protocol.c:47:12
#4 0x6373a2 in git_smart__connect libgit2/src/transports/smart.c:251:15
#5 0x57688f in git_remote_connect libgit2/src/remote.c:708:15
#6 0x52e59b in LLVMFuzzerTestOneInput /src/download_refs_fuzzer.cc:145:9
#7 0x52ef3f in ExecuteFilesOnyByOne(int, char**) /src/libfuzzer/afl/afl_driver.cpp:301:5
#8 0x52f4ee in main /src/libfuzzer/afl/afl_driver.cpp:339:12
#9 0x7f6c910db82f in __libc_start_main /build/glibc-Cl5G7W/glibc-2.23/csu/libc-start.c:291
#10 0x41d518 in _start
When parsing an "ng" packet, we keep track of both the current position
as well as the remaining length of the packet itself. But instead of
taking care not to exceed the length, we pass the current pointer's
position to `strchr`, which will search for a certain character until
hitting NUL. It is thus possible to create a crafted packet which
doesn't contain a NUL byte to trigger an out-of-bounds read.
Fix the issue by instead using `memchr`, passing the remaining length as
restriction. Furthermore, verify that we actually have enough bytes left
to produce a match at all.
OSS-Fuzz-Issue: 9406
|
|
b8408557
|
2018-06-29T16:53:23
|
|
Merge remote-tracking branch 'origin/master' into no-pkt-pack
|
|
|
895a668e
|
2018-06-28T05:27:36
|
|
Small style tweak, and set an error
|
|
|
12232a5e
|
2018-06-27T17:19:37
|
|
Merge pull request #4698 from nelhage/fix-leaks
Fix assorted leaks found via fuzzing
|
|
|
90cf8607
|
2018-06-26T02:32:50
|
|
Remove GIT_PKT_PACK entirely
|
|
|
3a547417
|
2018-06-25T15:38:29
|
|
git_pkt_free: Allow freeing NULL
|
|
|
437ee5a7
|
2018-06-24T19:47:08
|
|
Verify ref_pkt's are long enough
If the remote sends a too-short packet, we'll allow `len` to go
negative and eventually issue a malloc for <= 0 bytes on
```
pkt->head.name = git__malloc(alloclen);
```
|
|
|
ecf4f33a
|
2018-02-08T11:14:48
|
|
Convert usage of `git_buf_free` to new `git_buf_dispose`
|
|
a6d833a2
|
2017-01-13T17:05:58
|
|
Merge pull request #4049 from libgit2/ethomson/error_msgs
giterr_set: consistent error messages
|
|
|
2fdef641
|
2016-11-15T11:44:51
|
|
smart_pkt: treat empty packet lines as error
The Git protocol does not specify what should happen in the case
of an empty packet line (that is a packet line "0004"). We
currently indicate success, but do not return a packet in the
case where we hit an empty line. The smart protocol was not
prepared to handle such packets in all cases, though, resulting
in a `NULL` pointer dereference.
Fix the issue by returning an error instead. As such kind of
packets is not even specified by upstream, this is the right
thing to do.
|
|
|
66e3774d
|
2016-11-15T11:36:27
|
|
smart_pkt: verify packet length exceeds PKT_LEN_SIZE
Each packet line in the Git protocol is prefixed by a four-byte
length of how much data will follow, which we parse in
`git_pkt_parse_line`. The transmitted length can either be equal
to zero in case of a flush packet or has to be at least of length
four, as it also includes the encoded length itself. Not
checking this may result in a buffer overflow as we directly pass
the length to functions which accept a `size_t` length as
parameter.
Fix the issue by verifying that non-flush packets have at least a
length of `PKT_LEN_SIZE`.
|
|
909d5494
|
2016-12-29T12:25:15
|
|
giterr_set: consistent error messages
Error messages should be sentence fragments, and therefore:
1. Should not begin with a capital letter,
2. Should not conclude with punctuation, and
3. Should not end a sentence and begin a new one
|
|
|
7d02019a
|
2016-06-06T12:59:17
|
|
transports: smart: fix potential invalid memory dereferences
When we receive a packet of exactly four bytes encoding its
length as those four bytes it can be treated as an empty line.
While it is not really specified how those empty lines should be
treated, we currently ignore them and do not return an error when
trying to parse it but simply advance the data pointer.
Callers invoking `git_pkt_parse_line` are currently not prepared
to handle this case as they do not explicitly check this case.
While they could always reset the passed out-pointer to `NULL`
before calling `git_pkt_parse_line` and determine if the pointer
has been set afterwards, it makes more sense to update
`git_pkt_parse_line` to set the out-pointer to `NULL` itself when
it encounters such an empty packet. Like this it is guaranteed
that there will be no invalid memory references to free'd
pointers.
As such, the issue has been fixed such that `git_pkt_parse_line`
always sets the packet out pointer to `NULL` when an empty packet
has been received and callers check for this condition, skipping
such packets.
|
|
|
003c5e46
|
2016-02-22T15:52:49
|
|
transports: smart_pkt: fix memory leaks on error paths
|
|
|
6e2a3755
|
2016-02-23T11:45:43
|
|
smart_pkt: check buffer with GITERR_CHECK_ALLOC_BUF
|
|
|
b0f7512f
|
2016-02-15T11:46:10
|
|
transports: smart_pkt: fix memory leaks
|
|
2d1d2bb5
|
2015-08-05T18:50:25
|
|
Include the 4 characters not recognised as hex-number when setting error in parse_len
|
|
768f8be3
|
2015-06-30T19:00:41
|
|
Fix #3094 - improve use of portable size_t/ssize_t format specifiers.
The header src/cc-compat.h defines portable format specifiers PRIuZ, PRIdZ, and PRIxZ. The original report highlighted the need to use these specifiers in examples/network/fetch.c. For this commit, I checked all C source and header files not in deps/ and transitioned to the appropriate format specifier where appropriate.
|
|
f1453c59
|
2015-02-12T12:19:37
|
|
Make our overflow check look more like gcc/clang's
Make our overflow checking look more like gcc and clang's, so that
we can substitute it out with the compiler instrinsics on platforms
that support it. This means dropping the ability to pass `NULL` as
an out parameter.
As a result, the macros also get updated to reflect this as well.
|
|
|
ec3b4d35
|
2015-02-11T11:20:05
|
|
Use `size_t` to hold size of arrays
Use `size_t` to hold the size of arrays to ease overflow checking,
lest we check for overflow of a `size_t` then promptly truncate
by packing the length into a smaller type.
|
|
|
4aa664ae
|
2015-02-10T23:55:07
|
|
git_buf_grow_by: increase buf asize incrementally
Introduce `git_buf_grow_by` to incrementally increase the size of a
`git_buf`, performing an overflow calculation on the growth.
|
|
|
392702ee
|
2015-02-09T23:41:13
|
|
allocations: test for overflow of requested size
Introduce some helper macros to test integer overflow from arithmetic
and set error message appropriately.
|
|
306475eb
|
2014-05-20T09:55:26
|
|
remote: expose the remote's symref mappings
Add a symref_target field to git_remote_head to expose the symref
mappings to the user.
|
|
98020d3a
|
2014-04-21T10:55:37
|
|
Rename progress callback to sideband_progress
|
|
|
2f8c481c
|
2013-10-08T16:22:21
|
|
protocol: basic support for multi_ack_detailed
This tells the server that we speak it, but we don't make use of its
extra information to determine if there's a better place to stop
negotiating.
In a somewhat-related change, reorder the capabilities so we ask for
them in the same order as git does.
Also take this opportunity to factor out a fairly-indented portion of
the negotiation logic.
|
|
|
b4342b11
|
2013-10-04T10:27:45
|
|
net: advertise our support for fixing thin packs
|
|
b8c32580
|
2013-03-12T15:19:32
|
|
Advertise and support side-band-64k when calling receive-pack
|
|
|
359fc2d2
|
2013-01-08T17:07:25
|
|
update copyrights
|
|
|
6762fe08
|
2012-11-29T08:29:26
|
|
Remove casts of return values of type void *
|
|
|
613d5eb9
|
2012-11-28T11:42:37
|
|
Push! By schu, phkelley, and congyiwu, et al
|
|
|
41fb1ca0
|
2012-10-29T13:41:14
|
|
Reorganize transport architecture (squashed 3)
|