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author | Alexey Dobriyan <adobriyan@openvz.org> | 2007-02-10 09:44:39 (GMT) |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-11 18:51:24 (GMT) |
commit | 3ee75ac3c0f4904633322b7d9b111566fbc4a7d3 (patch) | |
tree | 2456021d63e95e92ce6bfae2e1f9d83c1843319d /kernel | |
parent | 8b6312f4dcc1efe7975731b6c47dd134282bd9ac (diff) | |
download | linux-fsl-qoriq-3ee75ac3c0f4904633322b7d9b111566fbc4a7d3.tar.xz |
[PATCH] sysctl_{,ms_}jiffies: fix oldlen semantics
currently it's
1) if *oldlenp == 0,
don't writeback anything
2) if *oldlenp >= table->maxlen,
don't writeback more than table->maxlen bytes and rewrite *oldlenp
don't look at underlying type granularity
3) if 0 < *oldlenp < table->maxlen,
*cough*
string sysctls don't writeback more than *oldlenp bytes.
OK, that's because sizeof(char) == 1
int sysctls writeback anything in (0, table->maxlen] range
Though accept integers divisible by sizeof(int) for writing.
sysctl_jiffies and sysctl_ms_jiffies don't writeback anything but
sizeof(int), which violates 1) and 2).
So, make sysctl_jiffies and sysctl_ms_jiffies accept
a) *oldlenp == 0, not doing writeback
b) *oldlenp >= sizeof(int), writing one integer.
-EINVAL still returned for *oldlenp == 1, 2, 3.
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/sysctl.c | 44 |
1 files changed, 28 insertions, 16 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 41bbba1..16ef870 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2553,17 +2553,23 @@ int sysctl_jiffies(ctl_table *table, int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, void __user *newval, size_t newlen) { - if (oldval) { + if (oldval && oldlenp) { size_t olen; - if (oldlenp) { - if (get_user(olen, oldlenp)) + + if (get_user(olen, oldlenp)) + return -EFAULT; + if (olen) { + int val; + + if (olen < sizeof(int)) + return -EINVAL; + + val = *(int *)(table->data) / HZ; + if (put_user(val, (int __user *)oldval)) + return -EFAULT; + if (put_user(sizeof(int), oldlenp)) return -EFAULT; - if (olen!=sizeof(int)) - return -EINVAL; } - if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) || - (oldlenp && put_user(sizeof(int),oldlenp))) - return -EFAULT; } if (newval && newlen) { int new; @@ -2581,17 +2587,23 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, void __user *newval, size_t newlen) { - if (oldval) { + if (oldval && oldlenp) { size_t olen; - if (oldlenp) { - if (get_user(olen, oldlenp)) + + if (get_user(olen, oldlenp)) + return -EFAULT; + if (olen) { + int val; + + if (olen < sizeof(int)) + return -EINVAL; + + val = jiffies_to_msecs(*(int *)(table->data)); + if (put_user(val, (int __user *)oldval)) + return -EFAULT; + if (put_user(sizeof(int), oldlenp)) return -EFAULT; - if (olen!=sizeof(int)) - return -EINVAL; } - if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) || - (oldlenp && put_user(sizeof(int),oldlenp))) - return -EFAULT; } if (newval && newlen) { int new; |