3.16.57-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Eric Biggers <[email protected]> commit 96e99be40e4cff870a83233731121ec0f7f95075 upstream. A pipe's size is represented as an 'unsigned int'. As expected, writing a value greater than UINT_MAX to /proc/sys/fs/pipe-max-size fails with EINVAL. However, the F_SETPIPE_SZ fcntl silently truncates such values to 32 bits, rather than failing with EINVAL as expected. (It *does* fail with EINVAL for values above (1 << 31) but <= UINT_MAX.) Fix this by moving the check against UINT_MAX into round_pipe_size() which is called in both cases. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Eric Biggers <[email protected]> Acked-by: Kees Cook <[email protected]> Acked-by: Joe Lawrence <[email protected]> Cc: Alexander Viro <[email protected]> Cc: "Luis R . Rodriguez" <[email protected]> Cc: Michael Kerrisk <[email protected]> Cc: Mikulas Patocka <[email protected]> Cc: Willy Tarreau <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- fs/pipe.c | 5 ++++- include/linux/pipe_fs_i.h | 2 +- kernel/sysctl.c | 3 --- 3 files changed, 5 insertions(+), 5 deletions(-) --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1008,10 +1008,13 @@ const struct file_operations pipefifo_fo * Currently we rely on the pipe array holding a power-of-2 number * of pages. Returns 0 on error. */ -unsigned int round_pipe_size(unsigned int size) +unsigned int round_pipe_size(unsigned long size) { unsigned long nr_pages; + if (size > UINT_MAX) + return 0; + /* Minimum pipe size, as required by POSIX */ if (size < PAGE_SIZE) size = PAGE_SIZE; --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -148,6 +148,6 @@ long pipe_fcntl(struct file *, unsigned struct pipe_inode_info *get_pipe_info(struct file *file); int create_pipe_files(struct file **, int); -unsigned int round_pipe_size(unsigned int size); +unsigned int round_pipe_size(unsigned long size); #endif --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2230,9 +2230,6 @@ static int do_proc_dopipe_max_size_conv( if (write) { unsigned int val; - if (*lvalp > UINT_MAX) - return -EINVAL; - val = round_pipe_size(*lvalp); if (*negp || val == 0) return -EINVAL;
