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From 780f79420073e0c09cd41afea28ac217a6d4ef29 Mon Sep 17 00:00:00 2001
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From: Karel Zak <kzak@redhat.com>
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Date: Fri, 26 Jun 2020 12:59:32 +0200
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Subject: [PATCH 49/55] libmount: (parser) fix memory leak on error before
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 end-of-file
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Let's simplify the loop where we add FS to the table. The optimization
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for recoverable errors is a fragile overkill. The new code always
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allocates and unrefs FS for each loop.
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Addresses: https://github.com/karelzak/util-linux/pull/1068
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Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1900498
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Upstream: http://github.com/karelzak/util-linux/commit/fe0d12d4f82269096f8d0cffc51ca9590814c284
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Signed-off-by: Karel Zak <kzak@redhat.com>
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---
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 libmount/src/fs.c        |  2 +-
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 libmount/src/tab_parse.c | 49 ++++++++++++++++++++++------------------
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 2 files changed, 28 insertions(+), 23 deletions(-)
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diff --git a/libmount/src/fs.c b/libmount/src/fs.c
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index def32253c..aae4961c3 100644
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--- a/libmount/src/fs.c
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+++ b/libmount/src/fs.c
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@@ -34,7 +34,7 @@ struct libmnt_fs *mnt_new_fs(void)
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 	fs->refcount = 1;
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 	INIT_LIST_HEAD(&fs->ents);
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-	/*DBG(FS, ul_debugobj(fs, "alloc"));*/
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+	DBG(FS, ul_debugobj(fs, "alloc"));
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 	return fs;
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 }
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diff --git a/libmount/src/tab_parse.c b/libmount/src/tab_parse.c
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index 10fc68279..719c1abca 100644
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--- a/libmount/src/tab_parse.c
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+++ b/libmount/src/tab_parse.c
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@@ -608,7 +608,6 @@ static int __table_parse_stream(struct libmnt_table *tb, FILE *f, const char *fi
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 	int rc = -1;
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 	int flags = 0;
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 	pid_t tid = -1;
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-	struct libmnt_fs *fs = NULL;
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 	struct libmnt_parser pa = { .line = 0 };
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 	assert(tb);
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@@ -628,19 +627,25 @@ static int __table_parse_stream(struct libmnt_table *tb, FILE *f, const char *fi
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 	if (filename && strcmp(filename, _PATH_PROC_MOUNTS) == 0)
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 		flags = MNT_FS_KERNEL;
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-	while (!feof(f)) {
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-		if (!fs) {
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-			fs = mnt_new_fs();
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-			if (!fs)
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-				goto err;
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+	do {
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+		struct libmnt_fs *fs;
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+
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+		if (feof(f)) {
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+			DBG(TAB, ul_debugobj(tb, "end-of-file"));
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+			break;
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 		}
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+		fs = mnt_new_fs();
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+		if (!fs)
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+			goto err;
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+		/* parse */
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 		rc = mnt_table_parse_next(&pa, tb, fs);
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-		if (!rc && tb->fltrcb && tb->fltrcb(fs, tb->fltrcb_data))
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-			rc = 1;	/* filtered out by callback... */
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+		if (rc != 0 && tb->fltrcb && tb->fltrcb(fs, tb->fltrcb_data))
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+			rc = 1;	/* error filtered out by callback... */
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-		if (!rc) {
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+		/* add to the table */
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+		if (rc == 0) {
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 			rc = mnt_table_add_fs(tb, fs);
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 			fs->flags |= flags;
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@@ -651,21 +656,21 @@ static int __table_parse_stream(struct libmnt_table *tb, FILE *f, const char *fi
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 			}
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 		}
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-		if (rc) {
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-			if (rc > 0) {
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-				mnt_reset_fs(fs);
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-				assert(fs->refcount == 1);
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-				continue;	/* recoverable error, reuse fs*/
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-			}
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+		/* remove refernece (or deallocate on error) */
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+		mnt_unref_fs(fs);
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-			mnt_unref_fs(fs);
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-			if (feof(f))
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-				break;
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-			goto err;		/* fatal error */
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+		/* recoverable error */
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+		if (rc > 0) {
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+			DBG(TAB, ul_debugobj(tb, "recoverable error (continue)"));
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+			continue;
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 		}
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-		mnt_unref_fs(fs);
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-		fs = NULL;
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-	}
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+
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+		/* fatal errors */
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+		if (rc < 0 && !feof(f)) {
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+			DBG(TAB, ul_debugobj(tb, "fatal error"));
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+			goto err;
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+		}
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+	} while (1);
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 	DBG(TAB, ul_debugobj(tb, "%s: stop parsing (%d entries)",
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 				filename, mnt_table_get_nents(tb)));
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-- 
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2.29.2
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