From 5116caf8fc868e061e074da65947a9ff6f856bff Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Fri, 16 Jun 2017 16:21:44 +0200 Subject: ubifs: Don't leak kernel memory to the MTD commit 4acadda74ff8b949c448c0282765ae747e088c87 upstream. When UBIFS prepares data structures which will be written to the MTD it ensues that their lengths are multiple of 8. Since it uses kmalloc() the padded bytes are left uninitialized and we leak a few bytes of kernel memory to the MTD. To make sure that all bytes are initialized, let's switch to kzalloc(). Kzalloc() is fine in this case because the buffers are not huge and in the IO path the performance bottleneck is anyway the MTD. Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Richard Weinberger Reviewed-by: Boris Brezillon Signed-off-by: Richard Weinberger [bwh: Backported to 3.16: - Drop change in ubifs_jnl_xrename() - Adjust context] Signed-off-by: Ben Hutchings --- fs/ubifs/journal.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 0e045e75abd8..2e93c33b1048 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -573,7 +573,7 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, aligned_dlen = ALIGN(dlen, 8); aligned_ilen = ALIGN(ilen, 8); len = aligned_dlen + aligned_ilen + UBIFS_INO_NODE_SZ; - dent = kmalloc(len, GFP_NOFS); + dent = kzalloc(len, GFP_NOFS); if (!dent) return -ENOMEM; @@ -956,7 +956,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8); if (old_dir != new_dir) len += plen; - dent = kmalloc(len, GFP_NOFS); + dent = kzalloc(len, GFP_NOFS); if (!dent) return -ENOMEM; @@ -1303,7 +1303,7 @@ int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host, hlen = host_ui->data_len + UBIFS_INO_NODE_SZ; len = aligned_xlen + UBIFS_INO_NODE_SZ + ALIGN(hlen, 8); - xent = kmalloc(len, GFP_NOFS); + xent = kzalloc(len, GFP_NOFS); if (!xent) return -ENOMEM; @@ -1410,7 +1410,7 @@ int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode, aligned_len1 = ALIGN(len1, 8); aligned_len = aligned_len1 + ALIGN(len2, 8); - ino = kmalloc(aligned_len, GFP_NOFS); + ino = kzalloc(aligned_len, GFP_NOFS); if (!ino) return -ENOMEM; -- cgit v1.2.3