This is a note to let you know that I've just added the patch titled
sysctl: add proc_dou8vec_minmax()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sysctl-add-proc_dou8vec_minmax.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0da0da145f7b2cfaf21882667de732e515b01f69
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Thu Mar 25 11:08:13 2021 -0700
sysctl: add proc_dou8vec_minmax()
[ Upstream commit cb9444130662c6c13022579c861098f212db2562 ]
Networking has many sysctls that could fit in one u8.
This patch adds proc_dou8vec_minmax() for this purpose.
Note that the .extra1 and .extra2 fields are pointing
to integers, because it makes conversions easier.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: dc5110c2d959 ("tcp: restrict net.ipv4.tcp_app_win")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index cd7c6c4af83ad..1655b7b2a5abe 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1106,6 +1106,11 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table)
err |= sysctl_err(path, table, "array not allowed");
}
+ if (table->proc_handler == proc_dou8vec_minmax) {
+ if (table->maxlen != sizeof(u8))
+ err |= sysctl_err(path, table, "array not allowed");
+ }
+
return err;
}
@@ -1121,6 +1126,7 @@ static int sysctl_check_table(const char *path, struct ctl_table *table)
(table->proc_handler == proc_douintvec) ||
(table->proc_handler == proc_douintvec_minmax) ||
(table->proc_handler == proc_dointvec_minmax) ||
+ (table->proc_handler == proc_dou8vec_minmax) ||
(table->proc_handler == proc_dointvec_jiffies) ||
(table->proc_handler == proc_dointvec_userhz_jiffies) ||
(table->proc_handler == proc_dointvec_ms_jiffies) ||
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 161eba9fd9122..4393de94cb32d 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -53,6 +53,8 @@ int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *);
int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,
size_t *lenp, loff_t *ppos);
+int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer,
+ size_t *lenp, loff_t *ppos);
int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);
int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,
loff_t *);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index d8b7b28463135..43e907f4cac79 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1061,6 +1061,65 @@ int proc_douintvec_minmax(struct ctl_table *table, int write,
do_proc_douintvec_minmax_conv, ¶m);
}
+/**
+ * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars
+ * values from/to the user buffer, treated as an ASCII string. Negative
+ * strings are not allowed.
+ *
+ * This routine will ensure the values are within the range specified by
+ * table->extra1 (min) and table->extra2 (max).
+ *
+ * Returns 0 on success or an error on write when the range check fails.
+ */
+int proc_dou8vec_minmax(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table tmp;
+ unsigned int min = 0, max = 255U, val;
+ u8 *data = table->data;
+ struct do_proc_douintvec_minmax_conv_param param = {
+ .min = &min,
+ .max = &max,
+ };
+ int res;
+
+ /* Do not support arrays yet. */
+ if (table->maxlen != sizeof(u8))
+ return -EINVAL;
+
+ if (table->extra1) {
+ min = *(unsigned int *) table->extra1;
+ if (min > 255U)
+ return -EINVAL;
+ }
+ if (table->extra2) {
+ max = *(unsigned int *) table->extra2;
+ if (max > 255U)
+ return -EINVAL;
+ }
+
+ tmp = *table;
+
+ tmp.maxlen = sizeof(val);
+ tmp.data = &val;
+ val = *data;
+ res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos,
+ do_proc_douintvec_minmax_conv, ¶m);
+ if (res)
+ return res;
+ if (write)
+ *data = val;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);
+
static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
unsigned int *valp,
int write, void *data)
@@ -1612,6 +1671,12 @@ int proc_douintvec_minmax(struct ctl_table *table, int write,
return -ENOSYS;
}
+int proc_dou8vec_minmax(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp, loff_t *ppos)
+{
+ return -ENOSYS;
+}
+
int proc_dointvec_jiffies(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
