From: Taesoo Kim <tsgatesv@gmail.com>
To: tytso@mit.edu, adilger.kernel@dilger.ca,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: taesoo@gatech.edu, changwoo@gatech.edu, sanidhya@gatech.edu,
blee@gatech.edu, csong84@gatech.edu,
Taesoo Kim <tsgatesv@gmail.com>
Subject: [PATCH 1/1] ext4: better error handling of kstrdup()
Date: Fri, 20 Mar 2015 17:21:54 -0400 [thread overview]
Message-ID: <1426886514-23522-1-git-send-email-tsgatesv@gmail.com> (raw)
Upon memory pressure, kstrdup() might fail and correctly
handle memory error, although current implementation do not
refer orig_data.
NOTE. fortunately the correct impl works, other than a
corner case where kstrdup() fails and kzalloc() succeeds;
it might record 'NULL' in the log.
Signed-off-by: Taesoo Kim <tsgatesv@gmail.com>
---
fs/ext4/super.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e061e66..e2a609c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3408,7 +3408,7 @@ static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
static int ext4_fill_super(struct super_block *sb, void *data, int silent)
{
- char *orig_data = kstrdup(data, GFP_KERNEL);
+ char *orig_data;
struct buffer_head *bh;
struct ext4_super_block *es = NULL;
struct ext4_sb_info *sbi;
@@ -3431,6 +3431,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
ext4_group_t first_not_zeroed;
+ orig_data = kstrdup(data, GFP_KERNEL);
+ if (!orig_data)
+ return -ENOMEM;
+
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
goto out_free_orig;
@@ -4843,6 +4847,8 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
int i, j;
#endif
char *orig_data = kstrdup(data, GFP_KERNEL);
+ if (!orig_data)
+ return -ENOMEM;
/* Store the original options */
old_sb_flags = sb->s_flags;
--
2.3.3
next reply other threads:[~2015-03-20 21:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-20 21:21 Taesoo Kim [this message]
2015-04-03 4:25 ` [PATCH 1/1] ext4: better error handling of kstrdup() Theodore Ts'o
2015-04-03 5:09 ` Theodore Ts'o
2015-04-03 17:44 ` Taesoo Kim
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