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authorAl Viro <viro@zeniv.linux.org.uk>2010-10-29 03:30:42 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2010-10-29 04:14:56 -0400
commitd893f1bc2a9f0f7dcb4b433452c59f9bedac0d7d (patch)
treeb3cf84a271ccb19529d83a544b6024bbb23a7801 /fs/namei.c
parenta4118ee1d80b527c385cadd14db79559efb8a493 (diff)
fix open/umount race
nameidata_to_filp() drops nd->path or transfers it to opened file. In the former case it's a Bad Idea(tm) to do mnt_drop_write() on nd->path.mnt, since we might race with umount and vfsmount in question might be gone already. Fix: don't drop it, then... IOW, have nameidata_to_filp() grab nd->path in case it transfers it to file and do path_drop() in callers. After they are through with accessing nd->path... Reported-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/namei.c b/fs/namei.c
index f7dbc06857ab..5362af9b7372 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1574,6 +1574,7 @@ static struct file *finish_open(struct nameidata *nd,
*/
if (will_truncate)
mnt_drop_write(nd->path.mnt);
+ path_put(&nd->path);
return filp;
exit:
@@ -1675,6 +1676,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
}
filp = nameidata_to_filp(nd);
mnt_drop_write(nd->path.mnt);
+ path_put(&nd->path);
if (!IS_ERR(filp)) {
error = ima_file_check(filp, acc_mode);
if (error) {