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authorEric Biggers <ebiggers@google.com>2018-02-07 02:42:00 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-07 05:32:47 +0300
commit96e99be40e4cff870a83233731121ec0f7f95075 (patch)
treedf5a16068f9dbec9b28f721cc4bd48f17f7630a4
parent9903a91c763ecdae333a04a9d89d79d2b8966503 (diff)
downloadlinux-96e99be40e4cff870a83233731121ec0f7f95075.tar.xz
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.c5
-rw-r--r--include/linux/pipe_fs_i.h2
-rw-r--r--kernel/sysctl.c3
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;