git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH 1/6] git-am: handle missing "author" when parsing commit

From
Jeff King <peff@peff.net>
Date
Sep 5, 2019, 22:50 UTC
Message-ID
<20190905225031.GA25657@sigill.intra.peff.net>
In-Reply-To
<20190905224859.GA28660@sigill.intra.peff.net>

We try to parse the "author" line out of a commit buffer. We handle the case that split_ident_line() doesn't work, but we don't do any error checking that we found an "author" line in the first place! This would cause us to segfault on such a corrupt object.

Let's put in an explicit NULL check (we can just die(), which is what a bogus split would do, too). As a bonus, this silences a warning when compiling with gcc 9.2.1 using "-flto -O3", which claims that ident_len may be uninitialized (it would only be if we had a NULL here).

Reported-by: Stephan Beyer <s-beyer@gmx.net>
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/am.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/builtin/am.c b/builtin/am.c
index 1aea657a7f..ee7305eaa6 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1272,7 +1272,9 @@ static void get_commit_info(struct am_state *state, struct commit *commit)
 	buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
 
 	ident_line = find_commit_header(buffer, "author", &ident_len);
-
+	if (!ident_line)
+		die(_("missing author line in commit %s"),
+		      oid_to_hex(&commit->object.oid));
 	if (split_ident_line(&id, ident_line, ident_len) < 0)
 		die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
 
-- 
2.23.0.463.g883b23b1c5
Previous: Jeff KingNext: Jeff King
Message 13 of 23 in “Fix maybe-uninitialized warnings found by gcc 9 -flto”
  1. Fix maybe-uninitialized warnings found by gcc 9 -fltoStephan Beyer, Sep 5, 2019
  2. René ScharfeSep 5, 2019
  3. Jeff KingSep 5, 2019
  4. René ScharfeSep 5, 2019
  5. Junio C HamanoSep 5, 2019
  6. René ScharfeSep 5, 2019
  7. Junio C HamanoSep 5, 2019
  8. Junio C HamanoSep 5, 2019
  9. Junio C HamanoSep 5, 2019
  10. Jeff KingSep 5, 2019
  11. Junio C HamanoSep 5, 2019
  12. Jeff KingSep 5, 2019
  13. 1/6 git-am: handle missing "author" when parsing commitJeff King, Sep 5, 2019
  14. 2/6 pack-objects: use object_id in packlist_alloc()Jeff King, Sep 5, 2019
  15. 3/6 bulk-checkin: zero-initialize hashfile_checkpointJeff King, Sep 5, 2019
  16. 4/6 diff-delta: set size out-parameter to 0 for NULL deltaJeff King, Sep 5, 2019
  17. Stephan BeyerSep 5, 2019
  18. Jeff KingSep 5, 2019
  19. Stephan BeyerSep 5, 2019
  20. Jeff KingSep 6, 2019
  21. 6/6 pack-objects: drop packlist index_pos optimizationJeff King, Sep 6, 2019
  22. 5/6 test-read-cache: drop namelen variableJeff King, Sep 5, 2019
  23. 6/6 pack-objects: drop packlist index_pos optimizationJeff King, Sep 5, 2019

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.