diff options
| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-03-03 11:04:03 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2017-04-18 16:58:37 +0200 |
| commit | 4e8c2eb54327a6f8b0ef6d6afb28ab24b721dbe0 (patch) | |
| tree | 2d5899fded4f7a002cc8ca492fa1742453f946c0 /fs/fuse | |
| parent | c1ae3cfa0e89fa1a7ecc4c99031f5e9ae99d9201 (diff) | |
fuse: convert fuse_file.count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse')
| -rw-r--r-- | fs/fuse/file.c | 8 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 3 |
2 files changed, 6 insertions, 5 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index ec238fb5a584..70770a0db734 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -58,7 +58,7 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) } INIT_LIST_HEAD(&ff->write_entry); - atomic_set(&ff->count, 1); + refcount_set(&ff->count, 1); RB_CLEAR_NODE(&ff->polled_node); init_waitqueue_head(&ff->poll_wait); @@ -77,7 +77,7 @@ void fuse_file_free(struct fuse_file *ff) static struct fuse_file *fuse_file_get(struct fuse_file *ff) { - atomic_inc(&ff->count); + refcount_inc(&ff->count); return ff; } @@ -88,7 +88,7 @@ static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req) static void fuse_file_put(struct fuse_file *ff, bool sync) { - if (atomic_dec_and_test(&ff->count)) { + if (refcount_dec_and_test(&ff->count)) { struct fuse_req *req = ff->reserved_req; if (ff->fc->no_open) { @@ -293,7 +293,7 @@ static int fuse_release(struct inode *inode, struct file *file) void fuse_sync_release(struct fuse_file *ff, int flags) { - WARN_ON(atomic_read(&ff->count) != 1); + WARN_ON(refcount_read(&ff->count) > 1); fuse_prepare_release(ff, flags, FUSE_RELEASE); /* * iput(NULL) is a no-op and since the refcount is 1 and everything's diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 32ac2c9b09c0..1d6d67e64f49 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -24,6 +24,7 @@ #include <linux/workqueue.h> #include <linux/kref.h> #include <linux/xattr.h> +#include <linux/refcount.h> /** Max number of pages that can be used in a single read request */ #define FUSE_MAX_PAGES_PER_REQ 32 @@ -137,7 +138,7 @@ struct fuse_file { u64 nodeid; /** Refcount */ - atomic_t count; + refcount_t count; /** FOPEN_* flags returned by open */ u32 open_flags; |