From ce0504b74d046da612f4758117eca0122c2ee225 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Sun, 1 Jul 2018 23:20:51 +0200 Subject: [PATCH] ubifs: Check data node size before truncate commit 95a22d2084d72ea067d8323cc85677dba5d97cae upstream. Check whether the size is within bounds before using it. If the size is not correct, abort and dump the bad data node. Cc: Kees Cook Cc: Silvio Cesare Cc: stable@vger.kernel.org Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system") Reported-by: Silvio Cesare Signed-off-by: Richard Weinberger Reviewed-by: Kees Cook Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- fs/ubifs/journal.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index da8afdfccaa6..eea12d25a58b 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1387,7 +1387,16 @@ int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode, else if (err) goto out_free; else { - if (le32_to_cpu(dn->size) <= dlen) + int dn_len = le32_to_cpu(dn->size); + + if (dn_len <= 0 || dn_len > UBIFS_BLOCK_SIZE) { + ubifs_err(c, "bad data node (block %u, inode %lu)", + blk, inode->i_ino); + ubifs_dump_node(c, dn); + goto out_free; + } + + if (dn_len <= dlen) dlen = 0; /* Nothing to do */ else { err = truncate_data_node(c, inode, blk, dn, &dlen);