diff options
| author | Eric Biggers <ebiggers@google.com> | 2018-02-07 00:42:00 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-07 03:32:47 +0100 |
| commit | 96e99be40e4cff870a83233731121ec0f7f95075 (patch) | |
| tree | df5a16068f9dbec9b28f721cc4bd48f17f7630a4 | |
| parent | pipe: fix off-by-one error when checking buffer limits (diff) | |
| download | linux-96e99be40e4cff870a83233731121ec0f7f95075.tar.xz linux-96e99be40e4cff870a83233731121ec0f7f95075.zip | |
pipe: reject F_SETPIPE_SZ with size over UINT_MAX
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/20180111052902.14409-6-ebiggers3@gmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/pipe.c | 5 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 2 | ||||
| -rw-r--r-- | kernel/sysctl.c | 3 |
3 files changed, 5 insertions, 5 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 46c30ac777da..817393d36244 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1020,10 +1020,13 @@ const struct file_operations pipefifo_fops = { * 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; diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 5028bd4b2c96..5a3bb3b7c9ad 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -190,6 +190,6 @@ long pipe_fcntl(struct file *, unsigned int, unsigned long arg); 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 diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 59f09ea3ca3e..f98f28c12020 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2623,9 +2623,6 @@ static int do_proc_dopipe_max_size_conv(unsigned long *lvalp, if (write) { unsigned int val; - if (*lvalp > UINT_MAX) - return -EINVAL; - val = round_pipe_size(*lvalp); if (val == 0) return -EINVAL; |