diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2022-09-01 15:10:05 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-26 12:34:38 +0200 |
| commit | dc7f225090c29a5f3b9419b1af32846a201555e7 (patch) | |
| tree | 7a213ded7c5d2917c49d02ef4a38279f2009f4d4 /fs | |
| parent | cedaf73c8bdaa666cd125257861155f273464a6f (diff) | |
NFSD: Protect against send buffer overflow in NFSv2 READDIR
[ Upstream commit 00b4492686e0497fdb924a9d4c8f6f99377e176c ]
Restore the previous limit on the @count argument to prevent a
buffer overflow attack.
Fixes: 53b1119a6e50 ("NFSD: Fix READDIR buffer overflow")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfsd/nfsproc.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c index 081cca405983..b009da1dcbb5 100644 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -557,12 +557,11 @@ static void nfsd_init_dirlist_pages(struct svc_rqst *rqstp, struct xdr_buf *buf = &resp->dirlist; struct xdr_stream *xdr = &resp->xdr; - count = clamp(count, (u32)(XDR_UNIT * 2), svc_max_payload(rqstp)); - memset(buf, 0, sizeof(*buf)); /* Reserve room for the NULL ptr & eof flag (-2 words) */ - buf->buflen = count - XDR_UNIT * 2; + buf->buflen = clamp(count, (u32)(XDR_UNIT * 2), (u32)PAGE_SIZE); + buf->buflen -= XDR_UNIT * 2; buf->pages = rqstp->rq_next_page; rqstp->rq_next_page++; |