Currently the argv is only allocated on the stack, and then assigned to
process->argv. When the start_subprocess function goes out of scope,
the local argv variable is eliminated from the stack, but the pointer is
still kept around in process->argv.
Much later when we try to access the same process->argv in
finish_command, this leads us to access a memory location that no longer
contains what we want. As argv0 is only used for printing errors, this
is not easily noticed in normal git operations. However when running
t0021-conversion.sh through valgrind, valgrind rightfully complains:
==21024== Invalid read of size 8
==21024== at 0x2ACF64: finish_command (run-command.c:869)
==21024== by 0x2D6B18: subprocess_exit_handler (sub-process.c:72)
==21024== by 0x2AB41E: cleanup_children (run-command.c:45)
==21024== by 0x2AB526: cleanup_children_on_exit (run-command.c:81)
==21024== by 0x54AD487: __run_exit_handlers (in /usr/lib/libc-2.26.so)
==21024== by 0x54AD4D9: exit (in /usr/lib/libc-2.26.so)
==21024== by 0x11A9EF: handle_builtin (git.c:550)
==21024== by 0x11ABCC: run_argv (git.c:602)
==21024== by 0x11AD8E: cmd_main (git.c:679)
==21024== by 0x1BF125: main (common-main.c:43)
==21024== Address 0x1ffeffec00 is on thread 1's stack
==21024== 1504 bytes below stack pointer
==21024==
These days, the child_process structure has its own args array, and
the standard way to set up its argv[] is to use that one, instead of
assigning to process->argv to point at an array that is outside.
Use that facility automatically fixes this issue.
Reported-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_oid_hex_from_objpath takes care of creating a oid from a
pathname. It does this by memcpy'ing the first two bytes of the path to
the "hex" string, then skipping the '/', and then copying the rest of the
path to the "hex" string. Currently it fails to increase the pointer to
the hex string, so the second memcpy invocation just mashes over what
was copied in the first one, and leaves the last two bytes in the string
uninitialized.
This breaks valgrind in t5540, although the test passes without
valgrind:
==5490== Use of uninitialised value of size 8
==5490== at 0x13C6B5: hexval (cache.h:1238)
==5490== by 0x13C6DB: hex2chr (cache.h:1247)
==5490== by 0x13C734: get_sha1_hex (hex.c:42)
==5490== by 0x13C78E: get_oid_hex (hex.c:53)
==5490== by 0x118BDA: get_oid_hex_from_objpath (http-push.c:1023)
==5490== by 0x118C92: process_ls_object (http-push.c:1038)
==5490== by 0x118E5B: handle_remote_ls_ctx (http-push.c:1077)
==5490== by 0x118227: xml_end_tag (http-push.c:815)
==5490== by 0x50C1448: ??? (in /usr/lib/libexpat.so.1.6.6)
==5490== by 0x50C221B: ??? (in /usr/lib/libexpat.so.1.6.6)
==5490== by 0x50BFBF2: ??? (in /usr/lib/libexpat.so.1.6.6)
==5490== by 0x50C0B24: ??? (in /usr/lib/libexpat.so.1.6.6)
==5490== Uninitialised value was created by a stack allocation
==5490== at 0x118B63: get_oid_hex_from_objpath (http-push.c:1012)
==5490==
Fix this by correctly incrementing the pointer to the "hex" variable, so
the first two bytes are left untouched by the memcpy call, and the last
two bytes are correctly initialized.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In cleanup_path we're passing in a char array, run a memcmp on it, and
run through it without ever checking if something is in the array in the
first place. This can lead us to access uninitialized memory, for
example in t5541-http-push-smart.sh test 7, when run under valgrind:
==4423== Conditional jump or move depends on uninitialised value(s)
==4423== at 0x242FA9: cleanup_path (path.c:35)
==4423== by 0x242FA9: mkpath (path.c:456)
==4423== by 0x256CC7: refname_match (refs.c:364)
==4423== by 0x26C181: count_refspec_match (remote.c:1015)
==4423== by 0x26C181: match_explicit_lhs (remote.c:1126)
==4423== by 0x26C181: check_push_refs (remote.c:1409)
==4423== by 0x2ABB4D: transport_push (transport.c:870)
==4423== by 0x186703: push_with_options (push.c:332)
==4423== by 0x18746D: do_push (push.c:409)
==4423== by 0x18746D: cmd_push (push.c:566)
==4423== by 0x1183E0: run_builtin (git.c:352)
==4423== by 0x11973E: handle_builtin (git.c:539)
==4423== by 0x11973E: run_argv (git.c:593)
==4423== by 0x11973E: main (git.c:698)
==4423== Uninitialised value was created by a heap allocation
==4423== at 0x4C2CD8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4423== by 0x4C2F195: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4423== by 0x2C196B: xrealloc (wrapper.c:137)
==4423== by 0x29A30B: strbuf_grow (strbuf.c:66)
==4423== by 0x29A30B: strbuf_vaddf (strbuf.c:277)
==4423== by 0x242F9F: mkpath (path.c:454)
==4423== by 0x256CC7: refname_match (refs.c:364)
==4423== by 0x26C181: count_refspec_match (remote.c:1015)
==4423== by 0x26C181: match_explicit_lhs (remote.c:1126)
==4423== by 0x26C181: check_push_refs (remote.c:1409)
==4423== by 0x2ABB4D: transport_push (transport.c:870)
==4423== by 0x186703: push_with_options (push.c:332)
==4423== by 0x18746D: do_push (push.c:409)
==4423== by 0x18746D: cmd_push (push.c:566)
==4423== by 0x1183E0: run_builtin (git.c:352)
==4423== by 0x11973E: handle_builtin (git.c:539)
==4423== by 0x11973E: run_argv (git.c:593)
==4423== by 0x11973E: main (git.c:698)
==4423==
Avoid this by using skip_prefix(), which knows not to go beyond the
end of the string.
Reported-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We run `git rev-parse` though the shell, and quote its
argument only with single-quotes. This prevents most
metacharacters from being a problem, but misses the obvious
case when $name itself has single-quotes in it. We can fix
this by applying the usual shell-quoting formula.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refnames can contain shell metacharacters which need to be
passed verbatim to sub-processes. Using safe_pipe_capture
skips the shell entirely.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-cvsserver script is old and largely unmaintained
these days. But git-shell allows untrusted users to run it
out of the box, significantly increasing its attack surface.
Let's drop it from git-shell's list of internal handlers so
that it cannot be run by default. This is not backwards
compatible. But given the age and development activity on
CVS-related parts of Git, this is likely to impact very few
users, while helping many more (i.e., anybody who runs
git-shell and had no intention of supporting CVS).
There's no configuration mechanism in git-shell for us to
add a boolean and flip it to "off". But there is a mechanism
for adding custom commands, and adding CVS support here is
fairly trivial. Let's document it to give guidance to
anybody who really is still running cvsserver.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This makes the script pass arguments that are derived from end-user
input in safer way when invoking subcommands.
Reported-by: joernchen <joernchen@phenoelit.de>
Signed-off-by: joernchen <joernchen@phenoelit.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As a preparation for replacing `command` with a call to this
function from outside GITCVS::updater package, move it to the main
package.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Doc fix.
* mg/format-ref-doc-fix:
Documentation/git-for-each-ref: clarify peeling of tags for --format
Documentation: use proper wording for ref format strings
"git archive" did not work well with pathspecs and the
export-ignore attribute.
We may want to resurrect the "we don't archive an empty directory"
bonus patch, but I do not mind merging the above early to 'next'
and leave it as a separate follow-up enhancement.
cf. <20170820090629.tumvqwzkromcykjf@sigill.intra.peff.net>
* rs/archive-excluded-directory:
archive: don't queue excluded directories
archive: factor out helper functions for handling attributes
t5001: add tests for export-ignore attributes and exclude pathspecs
Killing "git merge --edit" before the editor returns control left
the repository in a state with MERGE_MSG but without MERGE_HEAD,
which incorrectly tells the subsequent "git commit" that there was
a squash merge in progress. This has been fixed.
* mg/killed-merge:
merge: save merge state earlier
merge: split write_merge_state in two
merge: clarify call chain
Documentation/git-merge: explain --continue
"git apply" that is used as a better "patch -p1" failed to apply a
taken from a file with CRLF line endings to a file with CRLF line
endings. The root cause was because it misused convert_to_git()
that tried to do "safe-crlf" processing by looking at the index
entry at the same path, which is a nonsense---in that mode, "apply"
is not working on the data in (or derived from) the index at all.
This has been fixed.
* tb/apply-with-crlf:
apply: file commited with CRLF should roundtrip diff and apply
convert: add SAFE_CRLF_KEEP_CRLF
When handshake with a subprocess filter notices that the process
asked for an unknown capability, Git did not report what program
the offending subprocess was running. This has been corrected.
We may want a follow-up fix to tighten the error checking, though.
* cc/subprocess-handshake-missing-capabilities:
sub-process: print the cmd when a capability is unsupported
"git grep -L" and "git grep --quiet -L" reported different exit
codes; this has been corrected.
* as/grep-quiet-no-match-exit-code-fix:
git-grep: correct exit code with --quiet and -L
bash 4.4 or newer gave a warning on NUL byte in command
substitution done in "git stash"; this has been squelched.
* kd/stash-with-bash-4.4:
stash: prevent warning about null bytes in input
Johannes Sixt