Commit a31b3cff authored by Christian Schoenebeck's avatar Christian Schoenebeck Committed by Dominique Martinet
Browse files

net/9p: fix response size check in p9_check_errors() 

Since commit 60ece083 ("net/9p: allocate appropriate reduced message
buffers") it is no longer appropriate to check server's response size
against msize. Check against the previously allocated buffer capacity
instead.

- Omit this size check entirely for zero-copy messages, as those always
  allocate 4k (P9_ZC_HDR_SZ) linear buffers which are not used for actual
  payload and can be much bigger than 4k.

- Replace p9_debug() by pr_err() to make sure this message is always
  printed in case this error is triggered.

- Add 9p message type to error message to ease investigation.

Link: https://lkml.kernel.org/r/e0edec84b1c80119ae937ce854b4f5f6dbe2d08c.1669144861.git.linux_oss@crudebyte.com


Signed-off-by: default avatarChristian Schoenebeck <linux_oss@crudebyte.com>
Tested-by: default avatarStefano Stabellini <sstabellini@kernel.org>
Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarDominique Martinet <asmadeus@codewreck.org>
parent 8e4c2eee

net/9p/client.c

+3 −4
Original line number Diff line number Diff line
@@ -519,10 +519,9 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req) 
	int ecode;



	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);

	if (req->rc.size >= c->msize) {

		p9_debug(P9_DEBUG_ERROR,

			 "requested packet size too big: %d\n",

			 req->rc.size);

	if (req->rc.size > req->rc.capacity && !req->rc.zc) {

		pr_err("requested packet size too big: %d does not fit %zu (type=%d)\n",

		       req->rc.size, req->rc.capacity, req->rc.id);

		return -EIO;

	}

	/* dump the response from server