[PATCH] Handle memory issues with large files

[Samanta Navarro]

If an input file contains a line which is too large for heap, then it
can happen that no error is shown but the file is not further processed.
Such a condition should lead to error return value instead of being
silently treated as success.

Proof of Concept:

$ dd if=/dev/zero bs=1024 count=2048 | tr '\0' '#' > acl.txt
$ echo "invalid line" >> acl.txt
$ ulimit -d 1024
$ setfacl --restore=acl.txt
$ echo $?
0

The return value of setfacl should not be zero (success).
---
The error message states that "line 0" is not okay. Maybe this should
be adjusted as well.
---
 tools/parse.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/parse.c b/tools/parse.c
index f052400..0803812 100644
--- a/tools/parse.c
+++ b/tools/parse.c
@@ -447,8 +447,11 @@ read_acl_comments(
                        (*lineno)++;
 
                line = __acl_next_line(file);
-               if (line == NULL)
-                       break;
+               if (line == NULL) {
+                       if (feof(file))
+                               break;
+                       goto fail;
+               }
                
                comments_read = 1;
 
@@ -580,6 +583,8 @@ read_acl_seq(
 
        if (ferror(file))
                goto fail;
+       if (!feof(file) && line == NULL)
+               return -1;
        return 0;
 
 fail:
-- 
2.34.1