Theoretically possible that "%pg" will take all room for the j_devname
and hence the "-%lu" will go outside the boundary due to unconditional
sprintf() in use. To make this code more robust, replace two sequential
s*printf():s by a single call and then replace forbidden character.
It's possible to do this way, because '/' won't ever be in the result
of "-%lu".
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
fs/jbd2/journal.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 8ae419152ff6..6e17f8f94dfd 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1491,7 +1491,6 @@ journal_t *jbd2_journal_init_inode(struct inode *inode)
{
journal_t *journal;
sector_t blocknr;
- char *p;
int err = 0;
blocknr = 0;
@@ -1515,9 +1514,8 @@ journal_t *jbd2_journal_init_inode(struct inode *inode)
journal->j_inode = inode;
snprintf(journal->j_devname, sizeof(journal->j_devname),
- "%pg", journal->j_dev);
- p = strreplace(journal->j_devname, '/', '!');
- sprintf(p, "-%lu", journal->j_inode->i_ino);
+ "%pg-%lu", journal->j_dev, journal->j_inode->i_ino);
+ strreplace(journal->j_devname, '/', '!');
jbd2_stats_proc_init(journal);
return journal;
--
2.40.0.1.gaa8946217a0b
