From patchwork Mon Oct 17 20:40:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Fix BUG() in calc_seckey() From: Sachin Prabhu X-Patchwork-Id: 9380527 Message-Id: <1476736822-30098-1-git-send-email-sprabhu@redhat.com> To: linux-cifs Date: Mon, 17 Oct 2016 16:40:22 -0400 Andy Lutromirski's new virtually mapped kernel stack allocations moves kernel stacks the vmalloc area. This triggers the bug kernel BUG at ./include/linux/scatterlist.h:140! at calc_seckey()->sg_init() Signed-off-by: Sachin Prabhu Reviewed-by: Jeff Layton --- fs/cifs/cifsencrypt.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 8347c90..5eb0412 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -808,7 +808,11 @@ calc_seckey(struct cifs_ses *ses) struct crypto_skcipher *tfm_arc4; struct scatterlist sgin, sgout; struct skcipher_request *req; - unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */ + unsigned char *sec_key; + + sec_key = kmalloc(CIFS_SESS_KEY_SIZE, GFP_KERNEL); + if (sec_key == NULL) + return -ENOMEM; get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE); @@ -816,7 +820,7 @@ calc_seckey(struct cifs_ses *ses) if (IS_ERR(tfm_arc4)) { rc = PTR_ERR(tfm_arc4); cifs_dbg(VFS, "could not allocate crypto API arc4\n"); - return rc; + goto out; } rc = crypto_skcipher_setkey(tfm_arc4, ses->auth_key.response, @@ -854,7 +858,8 @@ calc_seckey(struct cifs_ses *ses) out_free_cipher: crypto_free_skcipher(tfm_arc4); - +out: + kfree(sec_key); return rc; }