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| author | Matthew Wilcox <willy@infradead.org> | 2019-04-05 14:02:10 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-11 12:22:45 +0200 |
| commit | 9557090582a33801349f0a0920a55d134a27e740 (patch) | |
| tree | b00054a031b80755978735b44bc6e0ad017a1859 /include/linux | |
| parent | 6f3433c47e8223c97746ad227d1e6f5531e0758a (diff) | |
| download | linux-9557090582a33801349f0a0920a55d134a27e740.tar.gz linux-9557090582a33801349f0a0920a55d134a27e740.tar.bz2 linux-9557090582a33801349f0a0920a55d134a27e740.zip | |
fs: prevent page refcount overflow in pipe_buf_get
commit 15fab63e1e57be9fdb5eec1bbc5916e9825e9acb upstream.
Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount. All
callers converted to handle a failure.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/pipe_fs_i.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 4f7129389855..c6ae0d5e9f0f 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -107,18 +107,20 @@ struct pipe_buf_operations { /* * Get a reference to the pipe buffer. */ - void (*get)(struct pipe_inode_info *, struct pipe_buffer *); + bool (*get)(struct pipe_inode_info *, struct pipe_buffer *); }; /** * pipe_buf_get - get a reference to a pipe_buffer * @pipe: the pipe that the buffer belongs to * @buf: the buffer to get a reference to + * + * Return: %true if the reference was successfully obtained. */ -static inline void pipe_buf_get(struct pipe_inode_info *pipe, +static inline __must_check bool pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { - buf->ops->get(pipe, buf); + return buf->ops->get(pipe, buf); } /** @@ -178,7 +180,7 @@ struct pipe_inode_info *alloc_pipe_info(void); void free_pipe_info(struct pipe_inode_info *); /* Generic pipe buffer ops functions */ -void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); +bool generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *); |