From ba413ab2ccc49e6aa1ebc3523a75635b5e4a0494 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Tue, 21 Aug 2012 09:20:49 +0200 Subject: fs/9p: avoid debug OOPS when reading a long symlink Reading a symlink longer than the given buffer, a p9_debug use would try to print the link name (not NUL-terminated) using a %s format. Use %.*s instead, and replace the strncpy+strnlen with functionally equivalent strlen+memcpy. Signed-off-by: Jim Meyering Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index cbf9dbb1b2a2..890bed538f9b 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1276,12 +1276,12 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) } /* copy extension buffer into buffer */ - strncpy(buffer, st->extension, buflen); + retval = min(strlen(st->extension)+1, (size_t)buflen); + memcpy(buffer, st->extension, retval); - p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n", - dentry->d_name.name, st->extension, buffer); + p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n", + dentry->d_name.name, st->extension, buflen, buffer); - retval = strnlen(buffer, buflen); done: p9stat_free(st); kfree(st); -- cgit v1.2.3-58-ga151 From e549c1337133e85a6d6bc868d2d141a61a80975c Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 7 Sep 2012 07:55:25 -0400 Subject: 9p: don't use __getname/__putname for uname/aname These are generally very small strings. We don't need an entire 4k allocation for each. Instead, just free and reallocate them on an as-needed basis. Note: This patch is untested since I don't have a 9p server available at the moment. It's mainly something I noticed while doing some getname/putname cleanup work. Signed-off-by: Jeff Layton Signed-off-by: Eric Van Hensbergen --- fs/9p/v9fs.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) (limited to 'fs') diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c index b85efa773949..b20af7465786 100644 --- a/fs/9p/v9fs.c +++ b/fs/9p/v9fs.c @@ -184,10 +184,20 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) v9ses->afid = option; break; case Opt_uname: - match_strlcpy(v9ses->uname, &args[0], PATH_MAX); + kfree(v9ses->uname); + v9ses->uname = match_strdup(&args[0]); + if (!v9ses->uname) { + ret = -ENOMEM; + goto free_and_return; + } break; case Opt_remotename: - match_strlcpy(v9ses->aname, &args[0], PATH_MAX); + kfree(v9ses->aname); + v9ses->aname = match_strdup(&args[0]); + if (!v9ses->aname) { + ret = -ENOMEM; + goto free_and_return; + } break; case Opt_nodevmap: v9ses->nodev = 1; @@ -287,21 +297,21 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, struct p9_fid *fid; int rc; - v9ses->uname = __getname(); + v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL); if (!v9ses->uname) return ERR_PTR(-ENOMEM); - v9ses->aname = __getname(); + v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL); if (!v9ses->aname) { - __putname(v9ses->uname); + kfree(v9ses->uname); return ERR_PTR(-ENOMEM); } init_rwsem(&v9ses->rename_sem); rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY); if (rc) { - __putname(v9ses->aname); - __putname(v9ses->uname); + kfree(v9ses->aname); + kfree(v9ses->uname); return ERR_PTR(rc); } @@ -309,8 +319,6 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, list_add(&v9ses->slist, &v9fs_sessionlist); spin_unlock(&v9fs_sessionlist_lock); - strcpy(v9ses->uname, V9FS_DEFUSER); - strcpy(v9ses->aname, V9FS_DEFANAME); v9ses->uid = ~0; v9ses->dfltuid = V9FS_DEFUID; v9ses->dfltgid = V9FS_DEFGID; @@ -412,8 +420,8 @@ void v9fs_session_close(struct v9fs_session_info *v9ses) kfree(v9ses->cachetag); } #endif - __putname(v9ses->uname); - __putname(v9ses->aname); + kfree(v9ses->uname); + kfree(v9ses->aname); bdi_destroy(&v9ses->bdi); -- cgit v1.2.3-58-ga151