Commit 3b79ef2c authored by Greg Kurz's avatar Greg Kurz
Browse files

9pfs: limit xattr size in xattrcreate 



We shouldn't allow guests to create extended attribute with arbitrary sizes.
On linux hosts, the limit is XATTR_SIZE_MAX. Let's use it.

Signed-off-by: default avatarGreg Kurz <groug@kaod.org>
parent 7e55d65c

hw/9pfs/9p.c

+6 −1
Original line number Diff line number Diff line
@@ -3247,7 +3247,7 @@ static void coroutine_fn v9fs_xattrcreate(void *opaque) 
{

    int flags;

    int32_t fid;

    int64_t size;

    uint64_t size;

    ssize_t err = 0;

    V9fsString name;

    size_t offset = 7;
@@ -3262,6 +3262,11 @@ static void coroutine_fn v9fs_xattrcreate(void *opaque) 
    }

    trace_v9fs_xattrcreate(pdu->tag, pdu->id, fid, name.data, size, flags);



    if (size > XATTR_SIZE_MAX) {

        err = -E2BIG;

        goto out_nofid;

    }



    file_fidp = get_fid(pdu, fid);

    if (file_fidp == NULL) {

        err = -EINVAL;

hw/9pfs/trace-events

+1 −1
Original line number Diff line number Diff line
@@ -42,6 +42,6 @@ v9fs_mkdir(uint16_t tag, uint8_t id, int32_t fid, char* name, int mode, uint32_t 
v9fs_mkdir_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int err) "tag %u id %u qid={type %d version %d path %"PRId64"} err %d"

v9fs_xattrwalk(uint16_t tag, uint8_t id, int32_t fid, int32_t newfid, char* name) "tag %d id %d fid %d newfid %d name %s"

v9fs_xattrwalk_return(uint16_t tag, uint8_t id, int64_t size) "tag %d id %d size %"PRId64

v9fs_xattrcreate(uint16_t tag, uint8_t id, int32_t fid, char* name, int64_t size, int flags) "tag %d id %d fid %d name %s size %"PRId64" flags %d"

v9fs_xattrcreate(uint16_t tag, uint8_t id, int32_t fid, char* name, uint64_t size, int flags) "tag %d id %d fid %d name %s size %"PRIu64" flags %d"

v9fs_readlink(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"

v9fs_readlink_return(uint16_t tag, uint8_t id, char* target) "tag %d id %d name %s"