Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.12 16/65] fuse: initialize the flock flag in fuse_file on allocation | Date | Mon, 14 Aug 2017 18:19:07 -0700 |
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4.12-stable review patch. If anyone has any objections, please let me know.
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From: Mateusz Jurczyk <mjurczyk@google.com>
commit 68227c03cba84a24faf8a7277d2b1a03c8959c2c upstream.
Before the patch, the flock flag could remain uninitialized for the lifespan of the fuse_file allocation. 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 <mjurczyk@google.com> Fixes: 37fb3a30b462 ("fuse: fix flock") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/fuse/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -46,7 +46,7 @@ struct fuse_file *fuse_file_alloc(struct { struct fuse_file *ff; - ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); + ff = kzalloc(sizeof(struct fuse_file), GFP_KERNEL); if (unlikely(!ff)) return NULL;
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