From: Li Qiang <liqiang...@360.cn> In 9pfs xattr read/write function, it mix to use unsigned/signed ,32/64 bits integers. This will causes oob read/write issues. This patch fix this.
Signed-off-by: Li Qiang <liqiang...@360.cn> --- hw/9pfs/9p.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index e4040dc..8b50bfb 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -1642,21 +1642,21 @@ static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp, { ssize_t err; size_t offset = 7; - int read_count; - int64_t xattr_len; + uint64_t read_count; + uint64_t xattr_len; V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); VirtQueueElement *elem = v->elems[pdu->idx]; xattr_len = fidp->fs.xattr.len; + if (xattr_len < off) { + read_count = 0; + goto over_read_count; + } read_count = xattr_len - off; if (read_count > max_count) { read_count = max_count; - } else if (read_count < 0) { - /* - * read beyond XATTR value - */ - read_count = 0; } +over_read_count: err = pdu_marshal(pdu, offset, "d", read_count); if (err < 0) { return err; @@ -1982,22 +1982,19 @@ static int v9fs_xattr_write(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp, { int i, to_copy; ssize_t err = 0; - int write_count; - int64_t xattr_len; + uint64_t write_count; + uint64_t xattr_len; size_t offset = 7; xattr_len = fidp->fs.xattr.len; + if (xattr_len < off) { + err = -ENOSPC; + goto out; + } write_count = xattr_len - off; if (write_count > count) { write_count = count; - } else if (write_count < 0) { - /* - * write beyond XATTR value len specified in - * xattrcreate - */ - err = -ENOSPC; - goto out; } err = pdu_marshal(pdu, offset, "d", write_count); if (err < 0) { -- 1.8.3.1