Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

This pull request mostly contains some more fixes to prevent buggy guests from
breaking QEMU.

# gpg: Signature made Tue 01 Nov 2016 11:26:42 GMT
# gpg:                using DSA key 0x02FC3AEB0101DBC2
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg:                 aka "Greg Kurz <groug@free.fr>"
# gpg:                 aka "Greg Kurz <gkurz@fr.ibm.com>"
# gpg:                 aka "Greg Kurz <gkurz@linux.vnet.ibm.com>"
# gpg:                 aka "Gregory Kurz (Groug) <groug@free.fr>"
# gpg:                 aka "Gregory Kurz (Cimai Technology) <gkurz@cimai.com>"
# gpg:                 aka "Gregory Kurz (Meiosys Technology) <gkurz@meiosys.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 2BD4 3B44 535E C0A7 9894  DBA2 02FC 3AEB 0101 DBC2

* remotes/gkurz/tags/for-upstream:
  9pfs: drop excessive error message from virtfs_reset()
  9pfs: don't BUG_ON() if fid is already opened
  9pfs: xattrcreate requires non-opened fids
  9pfs: limit xattr size in xattrcreate
  9pfs: fix integer overflow issue in xattr read/write
  9pfs: convert 'len/copied_len' field in V9fsXattr to the type of uint64_t
  9pfs: add xattrwalk_fid field in V9fsXattr struct

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 49 insertions, 38 deletions

diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index e88cf257a2..aea7e9d392 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -325,7 +325,7 @@ static int coroutine_fn v9fs_xattr_fid_clunk(V9fsPDU *pdu, V9fsFidState *fidp)
 {
     int retval = 0;
 
-    if (fidp->fs.xattr.copied_len == -1) {
+    if (fidp->fs.xattr.xattrwalk_fid) {
         /* getxattr/listxattr fid */
         goto free_value;
     }
@@ -535,7 +535,7 @@ static int coroutine_fn v9fs_mark_fids_unreclaim(V9fsPDU *pdu, V9fsPath *path)
 static void coroutine_fn virtfs_reset(V9fsPDU *pdu)
 {
     V9fsState *s = pdu->s;
-    V9fsFidState *fidp = NULL;
+    V9fsFidState *fidp;
 
     /* Free all fids */
     while (s->fid_list) {
@@ -548,11 +548,6 @@ static void coroutine_fn virtfs_reset(V9fsPDU *pdu)
             free_fid(pdu, fidp);
         }
     }
-    if (fidp) {
-        /* One or more unclunked fids found... */
-        error_report("9pfs:%s: One or more uncluncked fids "
-                     "found during reset", __func__);
-    }
 }
 
 #define P9_QID_TYPE_DIR         0x80
@@ -1361,7 +1356,10 @@ static void coroutine_fn v9fs_walk(void *opaque)
         memcpy(&qids[name_idx], &qid, sizeof(qid));
     }
     if (fid == newfid) {
-        BUG_ON(fidp->fid_type != P9_FID_NONE);
+        if (fidp->fid_type != P9_FID_NONE) {
+            err = -EINVAL;
+            goto out;
+        }
         v9fs_path_copy(&fidp->path, &path);
     } else {
         newfidp = alloc_fid(s, newfid);
@@ -1443,7 +1441,10 @@ static void coroutine_fn v9fs_open(void *opaque)
         err = -ENOENT;
         goto out_nofid;
     }
-    BUG_ON(fidp->fid_type != P9_FID_NONE);
+    if (fidp->fid_type != P9_FID_NONE) {
+        err = -EINVAL;
+        goto out;
+    }
 
     err = v9fs_co_lstat(pdu, &fidp->path, &stbuf);
     if (err < 0) {
@@ -1637,20 +1638,17 @@ 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;
     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
     VirtQueueElement *elem = v->elems[pdu->idx];
 
-    xattr_len = fidp->fs.xattr.len;
-    read_count = xattr_len - off;
+    if (fidp->fs.xattr.len < off) {
+        read_count = 0;
+    } else {
+        read_count = fidp->fs.xattr.len - off;
+    }
     if (read_count > max_count) {
         read_count = max_count;
-    } else if (read_count < 0) {
-        /*
-         * read beyond XATTR value
-         */
-        read_count = 0;
     }
     err = pdu_marshal(pdu, offset, "d", read_count);
     if (err < 0) {
@@ -1979,23 +1977,18 @@ 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;
     size_t offset = 7;
 
 
-    xattr_len = fidp->fs.xattr.len;
-    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
-         */
+    if (fidp->fs.xattr.len < off) {
         err = -ENOSPC;
         goto out;
     }
+    write_count = fidp->fs.xattr.len - off;
+    if (write_count > count) {
+        write_count = count;
+    }
     err = pdu_marshal(pdu, offset, "d", write_count);
     if (err < 0) {
         return err;
@@ -2548,7 +2541,10 @@ static int coroutine_fn v9fs_complete_rename(V9fsPDU *pdu, V9fsFidState *fidp,
             err = -ENOENT;
             goto out_nofid;
         }
-        BUG_ON(dirfidp->fid_type != P9_FID_NONE);
+        if (fidp->fid_type != P9_FID_NONE) {
+            err = -EINVAL;
+            goto out;
+        }
         v9fs_co_name_to_path(pdu, &dirfidp->path, name->data, &new_path);
     } else {
         old_name = fidp->path.data;
@@ -2620,7 +2616,10 @@ static void coroutine_fn v9fs_rename(void *opaque)
         err = -ENOENT;
         goto out_nofid;
     }
-    BUG_ON(fidp->fid_type != P9_FID_NONE);
+    if (fidp->fid_type != P9_FID_NONE) {
+        err = -EINVAL;
+        goto out;
+    }
     /* if fs driver is not path based, return EOPNOTSUPP */
     if (!(pdu->s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT)) {
         err = -EOPNOTSUPP;
@@ -3190,7 +3189,7 @@ static void coroutine_fn v9fs_xattrwalk(void *opaque)
          */
         xattr_fidp->fs.xattr.len = size;
         xattr_fidp->fid_type = P9_FID_XATTR;
-        xattr_fidp->fs.xattr.copied_len = -1;
+        xattr_fidp->fs.xattr.xattrwalk_fid = true;
         if (size) {
             xattr_fidp->fs.xattr.value = g_malloc(size);
             err = v9fs_co_llistxattr(pdu, &xattr_fidp->path,
@@ -3223,7 +3222,7 @@ static void coroutine_fn v9fs_xattrwalk(void *opaque)
          */
         xattr_fidp->fs.xattr.len = size;
         xattr_fidp->fid_type = P9_FID_XATTR;
-        xattr_fidp->fs.xattr.copied_len = -1;
+        xattr_fidp->fs.xattr.xattrwalk_fid = true;
         if (size) {
             xattr_fidp->fs.xattr.value = g_malloc(size);
             err = v9fs_co_lgetxattr(pdu, &xattr_fidp->path,
@@ -3255,7 +3254,7 @@ 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;
@@ -3270,22 +3269,33 @@ 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;
         goto out_nofid;
     }
+    if (file_fidp->fid_type != P9_FID_NONE) {
+        err = -EINVAL;
+        goto out_put_fid;
+    }
+
     /* Make the file fid point to xattr */
     xattr_fidp = file_fidp;
     xattr_fidp->fid_type = P9_FID_XATTR;
     xattr_fidp->fs.xattr.copied_len = 0;
+    xattr_fidp->fs.xattr.xattrwalk_fid = false;
     xattr_fidp->fs.xattr.len = size;
     xattr_fidp->fs.xattr.flags = flags;
     v9fs_string_init(&xattr_fidp->fs.xattr.name);
     v9fs_string_copy(&xattr_fidp->fs.xattr.name, &name);
-    g_free(xattr_fidp->fs.xattr.value);
     xattr_fidp->fs.xattr.value = g_malloc0(size);
     err = offset;
+out_put_fid:
     put_fid(pdu, file_fidp);
 out_nofid:
     pdu_complete(pdu, err);
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index 2523a445f8..3976b7fe3d 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -159,11 +159,12 @@ typedef struct V9fsConf
 
 typedef struct V9fsXattr
 {
-    int64_t copied_len;
-    int64_t len;
+    uint64_t copied_len;
+    uint64_t len;
     void *value;
     V9fsString name;
     int flags;
+    bool xattrwalk_fid;
 } V9fsXattr;
 
 typedef struct V9fsDir {
diff --git a/hw/9pfs/trace-events b/hw/9pfs/trace-events
index 48d3d8abed..fb4de3d465 100644
--- a/hw/9pfs/trace-events
+++ b/hw/9pfs/trace-events
@@ -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"