From f6d7acc1d9cae277b0379e8209eaefe59a3fbf79 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 04c4ec6483e5..b2419c855b47 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1388,7 +1388,16 @@ 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); -- 2.20.1