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a hyperfast web frontend for git written in c 

Avoid null pointer dereference in cgit_print_diff().

When calling cgit_print_diff() with a bad new_rev and a NULL old_rev,
checking for new_rev's parent commit will result in a null pointer
dereference. Returning on an invalid commit before dereferencing fixes
this. Spotted with clang-analyzer.

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
Lukas Fleischer cgit@cryptocrack.de
Tue, 05 Apr 2011 10:38:53 +0200
commit

9afc883297b0d0943e9b358d2299950f33e8e5ed

parent

a0bf375a1a9b74056a913f3687c6f5b42ad4acf6

1 files changed, 6 insertions(+), 2 deletions(-)

jump to
M ui-diff.c → ui-diff.c 
@@ -345,8 +345,10 @@ cgit_print_error(fmt("Bad object name: %s", new_rev));
 		return;
 	}
 	commit = lookup_commit_reference(new_rev_sha1);
-	if (!commit || parse_commit(commit))
+	if (!commit || parse_commit(commit)) {
 		cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(new_rev_sha1)));
+		return;
+	}
 
 	if (old_rev)
 		get_sha1(old_rev, old_rev_sha1);

@@ -362,8 +364,10 @@ cgit_print_error(fmt("Bad object name: %s", sha1_to_hex(old_rev_sha1)));
 			return;
 		}
 		commit2 = lookup_commit_reference(old_rev_sha1);
-		if (!commit2 || parse_commit(commit2))
+		if (!commit2 || parse_commit(commit2)) {
 			cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(old_rev_sha1)));
+			return;
+		}
 	}
 
 	if ((ctx.qry.ssdiff && !ctx.cfg.ssdiff) || (!ctx.qry.ssdiff && ctx.cfg.ssdiff))