Theoretically possible that "%pg" will take all room for the j_devname and hence the "-%lu" will go out 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". Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- fs/jbd2/journal.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 8ae419152ff6..00c0aa4a3a91 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1515,9 +1515,8 @@ 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
