* [PATCH] ncpfs: memory corruption in ncp_read_kernel() [not found] <CA+ygN1LiXW3uNuMS-eRv5Y_WJNyyr77+Rgycec4Y-Ju2VGrNWA@mail.gmail.com> @ 2018-03-19 11:07 ` Dan Carpenter 2018-03-19 13:56 ` Greg Kroah-Hartman 0 siblings, 1 reply; 2+ messages in thread From: Dan Carpenter @ 2018-03-19 11:07 UTC (permalink / raw) To: Petr Vandrovec Cc: devel, security, Greg Kroah-Hartman, netdev, Philippe Ombredanne, Thomas Gleixner, David S. Miller If the server is malicious then *bytes_read could be larger than the size of the "target" buffer. It would lead to memory corruption when we do the memcpy(). Reported-by: Dr Silvio Cesare of InfoSect <Silvio Cesare <silvio.cesare@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> diff --git a/drivers/staging/ncpfs/ncplib_kernel.c b/drivers/staging/ncpfs/ncplib_kernel.c index 804adfebba2f..3e047eb4cc7c 100644 --- a/drivers/staging/ncpfs/ncplib_kernel.c +++ b/drivers/staging/ncpfs/ncplib_kernel.c @@ -981,6 +981,10 @@ ncp_read_kernel(struct ncp_server *server, const char *file_id, goto out; } *bytes_read = ncp_reply_be16(server, 0); + if (*bytes_read > to_read) { + result = -EINVAL; + goto out; + } source = ncp_reply_data(server, 2 + (offset & 1)); memcpy(target, source, *bytes_read); ^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ncpfs: memory corruption in ncp_read_kernel() 2018-03-19 11:07 ` [PATCH] ncpfs: memory corruption in ncp_read_kernel() Dan Carpenter @ 2018-03-19 13:56 ` Greg Kroah-Hartman 0 siblings, 0 replies; 2+ messages in thread From: Greg Kroah-Hartman @ 2018-03-19 13:56 UTC (permalink / raw) To: Dan Carpenter Cc: devel, security, netdev, Philippe Ombredanne, Thomas Gleixner, Petr Vandrovec, David S. Miller On Mon, Mar 19, 2018 at 02:07:45PM +0300, Dan Carpenter wrote: > If the server is malicious then *bytes_read could be larger than the > size of the "target" buffer. It would lead to memory corruption when we > do the memcpy(). > > Reported-by: Dr Silvio Cesare of InfoSect <Silvio Cesare <silvio.cesare@gmail.com> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > diff --git a/drivers/staging/ncpfs/ncplib_kernel.c b/drivers/staging/ncpfs/ncplib_kernel.c > index 804adfebba2f..3e047eb4cc7c 100644 > --- a/drivers/staging/ncpfs/ncplib_kernel.c > +++ b/drivers/staging/ncpfs/ncplib_kernel.c Ugh, I have like 2 more months before I delete this code :) Anyway, nice find, and fix, I'll go queue it up now, thanks. greg k-h ^ permalink raw reply [flat|nested] 2+ messages in thread
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[not found] <CA+ygN1LiXW3uNuMS-eRv5Y_WJNyyr77+Rgycec4Y-Ju2VGrNWA@mail.gmail.com>
2018-03-19 11:07 ` [PATCH] ncpfs: memory corruption in ncp_read_kernel() Dan Carpenter
2018-03-19 13:56 ` Greg Kroah-Hartman
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