diff options
| author | David S. Miller | 2022-07-08 12:10:34 +0100 |
|---|---|---|
| committer | David S. Miller | 2022-07-08 12:10:34 +0100 |
| commit | 32b3ad1418ea53184ab7d652f13b5d66414d1bba (patch) | |
| tree | ab1e05b75bb9090148ce3c2473b9c3c1ccfd1f36 /kernel | |
| parent | 820b8963adaea34a87abbecb906d1f54c0aabfb7 (diff) | |
| parent | 73318c4b7dbd0e781aaababff17376b2894745c0 (diff) | |
Merge branch 'sysctl-data-races'
Kuniyuki Iwashima says:
====================
sysctl: Fix data-races around ipv4_table.
A sysctl variable is accessed concurrently, and there is always a chance
of data-race. So, all readers and writers need some basic protection to
avoid load/store-tearing.
The first half of this series changes some proc handlers used in ipv4_table
to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the
sysctl side. Then, the second half adds READ_ONCE() to the other readers
of ipv4_table.
Changes:
v2:
* Drop some changes that makes backporting difficult
* First cleanup patch
* Lockless helpers and .proc_handler changes
* Drop the tracing part for .sysctl_mem
* Steve already posted a fix
* Drop int-to-bool change for cipso
* Should be posted to net-next later
* Drop proc_dobool() change
* Can be included in another series
v1: https://lore.kernel.org/netdev/20220706052130.16368-1-kuniyu@amazon.com/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sysctl.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e52b6e372c60..bf9383d17e1b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -446,14 +446,14 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, if (*negp) { if (*lvalp > (unsigned long) INT_MAX + 1) return -EINVAL; - *valp = -*lvalp; + WRITE_ONCE(*valp, -*lvalp); } else { if (*lvalp > (unsigned long) INT_MAX) return -EINVAL; - *valp = *lvalp; + WRITE_ONCE(*valp, *lvalp); } } else { - int val = *valp; + int val = READ_ONCE(*valp); if (val < 0) { *negp = true; *lvalp = -(unsigned long)val; @@ -472,9 +472,9 @@ static int do_proc_douintvec_conv(unsigned long *lvalp, if (write) { if (*lvalp > UINT_MAX) return -EINVAL; - *valp = *lvalp; + WRITE_ONCE(*valp, *lvalp); } else { - unsigned int val = *valp; + unsigned int val = READ_ONCE(*valp); *lvalp = (unsigned long)val; } return 0; @@ -857,7 +857,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, if ((param->min && *param->min > tmp) || (param->max && *param->max < tmp)) return -EINVAL; - *valp = tmp; + WRITE_ONCE(*valp, tmp); } return 0; @@ -923,7 +923,7 @@ static int do_proc_douintvec_minmax_conv(unsigned long *lvalp, (param->max && *param->max < tmp)) return -ERANGE; - *valp = tmp; + WRITE_ONCE(*valp, tmp); } return 0; @@ -1090,9 +1090,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, err = -EINVAL; break; } - *i = val; + WRITE_ONCE(*i, val); } else { - val = convdiv * (*i) / convmul; + val = convdiv * READ_ONCE(*i) / convmul; if (!first) proc_put_char(&buffer, &left, '\t'); proc_put_long(&buffer, &left, val, false); @@ -1173,9 +1173,12 @@ static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp, if (write) { if (*lvalp > INT_MAX / HZ) return 1; - *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ); + if (*negp) + WRITE_ONCE(*valp, -*lvalp * HZ); + else + WRITE_ONCE(*valp, *lvalp * HZ); } else { - int val = *valp; + int val = READ_ONCE(*valp); unsigned long lval; if (val < 0) { *negp = true; |