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authorChris Metcalf <cmetcalf@ezchip.com>2015-06-25 15:02:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 17:00:40 -0700
commit2528a8b8f457d7432552d0e2b6f0f4046bb702f4 (patch)
treea9656e593920e8cceabca160046c9ab65d7456a0 /lib/bitmap.c
parent4f973c63d158b9293f7dc16f54e119d75bc20380 (diff)
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__bitmap_parselist: fix bug in empty string handling
bitmap_parselist("", &mask, nmaskbits) will erroneously set bit zero in the mask. The same bug is visible in cpumask_parselist() since it is layered on top of the bitmask code, e.g. if you boot with "isolcpus=", you will actually end up with cpu zero isolated. The bug was introduced in commit 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq") when bitmap_parselist() was generalized to support userspace as well as kernelspace. Fixes: 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq") Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/bitmap.c')
-rw-r--r--lib/bitmap.c17
1 files changed, 9 insertions, 8 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 64c0926f5dd8..40162f87ea2d 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -506,12 +506,12 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
unsigned a, b;
int c, old_c, totaldigits;
const char __user __force *ubuf = (const char __user __force *)buf;
- int exp_digit, in_range;
+ int at_start, in_range;
totaldigits = c = 0;
bitmap_zero(maskp, nmaskbits);
do {
- exp_digit = 1;
+ at_start = 1;
in_range = 0;
a = b = 0;
@@ -540,11 +540,10 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
break;
if (c == '-') {
- if (exp_digit || in_range)
+ if (at_start || in_range)
return -EINVAL;
b = 0;
in_range = 1;
- exp_digit = 1;
continue;
}
@@ -554,16 +553,18 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
b = b * 10 + (c - '0');
if (!in_range)
a = b;
- exp_digit = 0;
+ at_start = 0;
totaldigits++;
}
if (!(a <= b))
return -EINVAL;
if (b >= nmaskbits)
return -ERANGE;
- while (a <= b) {
- set_bit(a, maskp);
- a++;
+ if (!at_start) {
+ while (a <= b) {
+ set_bit(a, maskp);
+ a++;
+ }
}
} while (buflen && c == ',');
return 0;