Add initialization of the flock flag in the fuse_file structure after it is allocated.
Before the patch, the flock flag could remain uninitialized for the lifespan of the fuse_file allocation: it was not pre-set by kmalloc() or later in the fuse_file_alloc() function. Unless set to true in fuse_file_flock(), it would remain in an indeterminate state until read in an if statement in fuse_release_common(). This could consequently lead to taking an unexpected branch in the code. The bug was discovered by a runtime instrumentation designed to detect use of uninitialized memory in the kernel. Signed-off-by: Mateusz Jurczyk <[email protected]> --- fs/fuse/file.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 3ee4fdc3da9e..c9a86a748ceb 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -66,6 +66,8 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) ff->kh = ++fc->khctr; spin_unlock(&fc->lock); + ff->flock = false; + return ff; } -- 2.13.1.508.gb3defc5cc-goog
