The patch titled
Subject: sysctl: fold sysctl_writes_strict checks into helper
has been added to the -mm tree. Its filename is
sysctl-fold-sysctl_writes_strict-checks-into-helper.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/sysctl-fold-sysctl_writes_strict-checks-into-helper.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/sysctl-fold-sysctl_writes_strict-checks-into-helper.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Luis R. Rodriguez" <mcgrof@xxxxxxxxxx>
Subject: sysctl: fold sysctl_writes_strict checks into helper
The mode sysctl_writes_strict positional checks keep being copy and pasted
as we add new proc handlers. Just add a helper to avoid code duplication.
Link: http://lkml.kernel.org/r/20170519033554.18592-4-mcgrof@xxxxxxxxxx
Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/sysctl.c | 56 ++++++++++++++++++++++++++--------------------
1 file changed, 32 insertions(+), 24 deletions(-)
diff -puN kernel/sysctl.c~sysctl-fold-sysctl_writes_strict-checks-into-helper kernel/sysctl.c
--- a/kernel/sysctl.c~sysctl-fold-sysctl_writes_strict-checks-into-helper
+++ a/kernel/sysctl.c
@@ -1971,6 +1971,32 @@ static void warn_sysctl_write(struct ctl
}
/**
+ * proc_first_pos_non_zero_ignore - check if firs position is allowed
+ * @ppos: file position
+ * @table: the sysctl table
+ *
+ * Returns true if the first position is non-zero and the sysctl_writes_strict
+ * mode indicates this is not allowed for numeric input types. String proc
+ * hadlers can ignore the return value.
+ */
+static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
+ struct ctl_table *table)
+{
+ if (!*ppos)
+ return false;
+
+ switch (sysctl_writes_strict) {
+ case SYSCTL_WRITES_STRICT:
+ return true;
+ case SYSCTL_WRITES_WARN:
+ warn_sysctl_write(table);
+ return false;
+ default:
+ return false;
+ }
+}
+
+/**
* proc_dostring - read a string sysctl
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
@@ -1990,8 +2016,8 @@ static void warn_sysctl_write(struct ctl
int proc_dostring(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
- if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
- warn_sysctl_write(table);
+ if (write)
+ proc_first_pos_non_zero_ignore(ppos, table);
return _proc_do_string((char *)(table->data), table->maxlen, write,
(char __user *)buffer, lenp, ppos);
@@ -2193,17 +2219,8 @@ static int __do_proc_dointvec(void *tbl_
conv = do_proc_dointvec_conv;
if (write) {
- if (*ppos) {
- switch (sysctl_writes_strict) {
- case SYSCTL_WRITES_STRICT:
- goto out;
- case SYSCTL_WRITES_WARN:
- warn_sysctl_write(table);
- break;
- default:
- break;
- }
- }
+ if (proc_first_pos_non_zero_ignore(ppos, table))
+ goto out;
if (left > PAGE_SIZE - 1)
left = PAGE_SIZE - 1;
@@ -2468,17 +2485,8 @@ static int __do_proc_doulongvec_minmax(v
left = *lenp;
if (write) {
- if (*ppos) {
- switch (sysctl_writes_strict) {
- case SYSCTL_WRITES_STRICT:
- goto out;
- case SYSCTL_WRITES_WARN:
- warn_sysctl_write(table);
- break;
- default:
- break;
- }
- }
+ if (proc_first_pos_non_zero_ignore(ppos, table))
+ goto out;
if (left > PAGE_SIZE - 1)
left = PAGE_SIZE - 1;
_
Patches currently in -mm which might be from mcgrof@xxxxxxxxxx are
sysctl-fix-lax-sysctl_check_table-sanity-check.patch
sysctl-kdocify-sysctl_writes_strict.patch
sysctl-fold-sysctl_writes_strict-checks-into-helper.patch
sysctl-simplify-unsigned-int-support.patch
sysctl-add-unsigned-int-range-support.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
