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authorDave Reisner <dreisner@archlinux.org>2012-09-08 11:55:45 -0400
committerJens Axboe <axboe@kernel.dk>2012-09-09 10:39:18 +0200
commitb1f3b64d76cf88cc250e5cdd1de783ba9737078e (patch)
treec7ec8496a2b9a8af239fa78090f65178f30063c7 /block
parentbf800ef1816b4283a885e55ad38068aec9711e4d (diff)
downloadvexpress-lsk-b1f3b64d76cf88cc250e5cdd1de783ba9737078e.tar.gz
block: reject invalid queue attribute values
Instead of using simple_strtoul which "converts" invalid numbers to 0, use strict_strtoul and perform error checking to ensure that userspace passes us a valid unsigned long. This addresses problems with functions such as writev, which might want to write a trailing newline -- the newline should rightfully be rejected, but the value preceeding it should be preserved. Fixes BZ#46981. Signed-off-by: Dave Reisner <dreisner@archlinux.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-sysfs.c25
1 files changed, 23 insertions, 2 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 9628b291f96..ea51d827a0b 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -26,9 +26,15 @@ queue_var_show(unsigned long var, char *page)
static ssize_t
queue_var_store(unsigned long *var, const char *page, size_t count)
{
- char *p = (char *) page;
+ int err;
+ unsigned long v;
+
+ err = strict_strtoul(page, 10, &v);
+ if (err || v > UINT_MAX)
+ return -EINVAL;
+
+ *var = v;
- *var = simple_strtoul(p, &p, 10);
return count;
}
@@ -48,6 +54,9 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
return -EINVAL;
ret = queue_var_store(&nr, page, count);
+ if (ret < 0)
+ return ret;
+
if (nr < BLKDEV_MIN_RQ)
nr = BLKDEV_MIN_RQ;
@@ -102,6 +111,9 @@ queue_ra_store(struct request_queue *q, const char *page, size_t count)
unsigned long ra_kb;
ssize_t ret = queue_var_store(&ra_kb, page, count);
+ if (ret < 0)
+ return ret;
+
q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
return ret;
@@ -176,6 +188,9 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
+ if (ret < 0)
+ return ret;
+
if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
return -EINVAL;
@@ -236,6 +251,9 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
unsigned long nm;
ssize_t ret = queue_var_store(&nm, page, count);
+ if (ret < 0)
+ return ret;
+
spin_lock_irq(q->queue_lock);
queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
@@ -264,6 +282,9 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
unsigned long val;
ret = queue_var_store(&val, page, count);
+ if (ret < 0)
+ return ret;
+
spin_lock_irq(q->queue_lock);
if (val == 2) {
queue_flag_set(QUEUE_FLAG_SAME_COMP, q);