diff options
| author |   Chuck Lever <chuck.lever@oracle.com> | 2022-09-01 15:10:05 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2022-09-26 14:02:26 -0400 |
| commit | 00b4492686e0497fdb924a9d4c8f6f99377e176c (patch) | |
| tree | 9eca05370c89e05c5616625dd2de3e31d26e634d | |
| parent | SUNRPC: Fix svcxdr_init_encode's buflen calculation (diff) | |
| download | linux-dev-00b4492686e0497fdb924a9d4c8f6f99377e176c.tar.xz linux-dev-00b4492686e0497fdb924a9d4c8f6f99377e176c.zip | |
NFSD: Protect against send buffer overflow in NFSv2 READDIR
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>
| -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 7381972f1677..ddb1902c0a18 100644 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -567,12 +567,11 @@ 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++; |