From 4acadda74ff8b949c448c0282765ae747e088c87 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Fri, 16 Jun 2017 16:21:44 +0200 Subject: [PATCH] ubifs: Don't leak kernel memory to the MTD 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. Cc: stable@vger.kernel.org Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Richard Weinberger Reviewed-by: Boris Brezillon Signed-off-by: Richard Weinberger --- fs/ubifs/journal.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 419c79ff377e1..9f356432f35f9 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -572,7 +572,7 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, /* Make sure to also account for extended attributes */ len += host_ui->data_len; - dent = kmalloc(len, GFP_NOFS); + dent = kzalloc(len, GFP_NOFS); if (!dent) return -ENOMEM; @@ -968,7 +968,7 @@ int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, if (twoparents) len += plen; - dent1 = kmalloc(len, GFP_NOFS); + dent1 = kzalloc(len, GFP_NOFS); if (!dent1) return -ENOMEM; @@ -1116,7 +1116,7 @@ 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 (move) len += plen; - dent = kmalloc(len, GFP_NOFS); + dent = kzalloc(len, GFP_NOFS); if (!dent) return -ENOMEM; @@ -1498,7 +1498,7 @@ 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; @@ -1605,7 +1605,7 @@ 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; -- 2.39.5