The patch titled
Subject: pipe, sysctl: drop 'min' parameter from pipe-max-size converter
has been added to the -mm tree. Its filename is
pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter.patch
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------------------------------------------------------
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Subject: pipe, sysctl: drop 'min' parameter from pipe-max-size converter
Patch series "pipe: buffer limits fixes and cleanups", v2.
This series simplifies the sysctl handler for pipe-max-size and fixes
another set of bugs related to the pipe buffer limits:
- The root user wasn't allowed to exceed the limits when creating new
pipes.
- There was an off-by-one error when checking the limits, so a limit of
N was actually treated as N - 1.
- F_SETPIPE_SZ accepted values over UINT_MAX.
- Reading the pipe buffer limits could be racy.
This patch (of 7):
Before validating the given value against pipe_min_size,
do_proc_dopipe_max_size_conv() calls round_pipe_size(), which rounds the
value up to pipe_min_size. Therefore, the second check against
pipe_min_size is redundant. Remove it.
Link: http://lkml.kernel.org/r/20180111052902.14409-2-ebiggers3@xxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: "Luis R . Rodriguez" <mcgrof@xxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: Willy Tarreau <w@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/pipe.c | 10 +++-------
include/linux/pipe_fs_i.h | 2 +-
kernel/sysctl.c | 15 +--------------
3 files changed, 5 insertions(+), 22 deletions(-)
diff -puN fs/pipe.c~pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter fs/pipe.c
--- a/fs/pipe.c~pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter
+++ a/fs/pipe.c
@@ -35,11 +35,6 @@
*/
unsigned int pipe_max_size = 1048576;
-/*
- * Minimum pipe size, as required by POSIX
- */
-unsigned int pipe_min_size = PAGE_SIZE;
-
/* Maximum allocatable pages per user. Hard limit is unset by default, soft
* matches default values.
*/
@@ -1024,8 +1019,9 @@ unsigned int round_pipe_size(unsigned in
{
unsigned long nr_pages;
- if (size < pipe_min_size)
- size = pipe_min_size;
+ /* Minimum pipe size, as required by POSIX */
+ if (size < PAGE_SIZE)
+ size = PAGE_SIZE;
nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
if (nr_pages == 0)
diff -puN include/linux/pipe_fs_i.h~pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter include/linux/pipe_fs_i.h
--- a/include/linux/pipe_fs_i.h~pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter
+++ a/include/linux/pipe_fs_i.h
@@ -167,7 +167,7 @@ void pipe_lock(struct pipe_inode_info *)
void pipe_unlock(struct pipe_inode_info *);
void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
-extern unsigned int pipe_max_size, pipe_min_size;
+extern unsigned int pipe_max_size;
extern unsigned long pipe_user_pages_hard;
extern unsigned long pipe_user_pages_soft;
int pipe_proc_fn(struct ctl_table *, int, void __user *, size_t *, loff_t *);
diff -puN kernel/sysctl.c~pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter kernel/sysctl.c
--- a/kernel/sysctl.c~pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter
+++ a/kernel/sysctl.c
@@ -1813,7 +1813,6 @@ static struct ctl_table fs_table[] = {
.maxlen = sizeof(pipe_max_size),
.mode = 0644,
.proc_handler = &pipe_proc_fn,
- .extra1 = &pipe_min_size,
},
{
.procname = "pipe-user-pages-hard",
@@ -2615,16 +2614,10 @@ int proc_douintvec_minmax(struct ctl_tab
do_proc_douintvec_minmax_conv, ¶m);
}
-struct do_proc_dopipe_max_size_conv_param {
- unsigned int *min;
-};
-
static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
unsigned int *valp,
int write, void *data)
{
- struct do_proc_dopipe_max_size_conv_param *param = data;
-
if (write) {
unsigned int val;
@@ -2635,9 +2628,6 @@ static int do_proc_dopipe_max_size_conv(
if (val == 0)
return -EINVAL;
- if (param->min && *param->min > val)
- return -ERANGE;
-
*valp = val;
} else {
unsigned int val = *valp;
@@ -2650,11 +2640,8 @@ static int do_proc_dopipe_max_size_conv(
int proc_dopipe_max_size(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
- struct do_proc_dopipe_max_size_conv_param param = {
- .min = (unsigned int *) table->extra1,
- };
return do_proc_douintvec(table, write, buffer, lenp, ppos,
- do_proc_dopipe_max_size_conv, ¶m);
+ do_proc_dopipe_max_size_conv, NULL);
}
static void validate_coredump_safety(void)
_
Patches currently in -mm which might be from ebiggers@xxxxxxxxxx are
userfaultfd-convert-to-use-anon_inode_getfd.patch
pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter.patch
pipe-sysctl-remove-pipe_proc_fn.patch
pipe-actually-allow-root-to-exceed-the-pipe-buffer-limits.patch
pipe-fix-off-by-one-error-when-checking-buffer-limits.patch
pipe-reject-f_setpipe_sz-with-size-over-uint_max.patch
pipe-simplify-round_pipe_size.patch
pipe-read-buffer-limits-atomically.patch
--
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