Commit 2528a8b8 authored by Chris Metcalf's avatar Chris Metcalf Committed by Linus Torvalds
Browse files

__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 4b060420 ("bitmap, irq: add
smp_affinity_list interface to /proc/irq") when bitmap_parselist() was
generalized to support userspace as well as kernelspace.

Fixes: 4b060420

 ("bitmap, irq: add smp_affinity_list interface to /proc/irq")
Signed-off-by: default avatarChris Metcalf <cmetcalf@ezchip.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4f973c63
...@@ -506,12 +506,12 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen, ...@@ -506,12 +506,12 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
unsigned a, b; unsigned a, b;
int c, old_c, totaldigits; int c, old_c, totaldigits;
const char __user __force *ubuf = (const char __user __force *)buf; const char __user __force *ubuf = (const char __user __force *)buf;
int exp_digit, in_range; int at_start, in_range;
totaldigits = c = 0; totaldigits = c = 0;
bitmap_zero(maskp, nmaskbits); bitmap_zero(maskp, nmaskbits);
do { do {
exp_digit = 1; at_start = 1;
in_range = 0; in_range = 0;
a = b = 0; a = b = 0;
...@@ -540,11 +540,10 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen, ...@@ -540,11 +540,10 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
break; break;
if (c == '-') { if (c == '-') {
if (exp_digit || in_range) if (at_start || in_range)
return -EINVAL; return -EINVAL;
b = 0; b = 0;
in_range = 1; in_range = 1;
exp_digit = 1;
continue; continue;
} }
...@@ -554,16 +553,18 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen, ...@@ -554,16 +553,18 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
b = b * 10 + (c - '0'); b = b * 10 + (c - '0');
if (!in_range) if (!in_range)
a = b; a = b;
exp_digit = 0; at_start = 0;
totaldigits++; totaldigits++;
} }
if (!(a <= b)) if (!(a <= b))
return -EINVAL; return -EINVAL;
if (b >= nmaskbits) if (b >= nmaskbits)
return -ERANGE; return -ERANGE;
while (a <= b) { if (!at_start) {
set_bit(a, maskp); while (a <= b) {
a++; set_bit(a, maskp);
a++;
}
} }
} while (buflen && c == ','); } while (buflen && c == ',');
return 0; return 0;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment