diff options
author | Dave Reisner <dreisner@archlinux.org> | 2012-09-08 17:55:45 +0200 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2012-09-09 10:39:18 +0200 |
commit | b1f3b64d76cf88cc250e5cdd1de783ba9737078e (patch) | |
tree | c7ec8496a2b9a8af239fa78090f65178f30063c7 /block | |
parent | block: Add bio_clone_bioset(), bio_clone_kmalloc() (diff) | |
download | linux-b1f3b64d76cf88cc250e5cdd1de783ba9737078e.tar.xz linux-b1f3b64d76cf88cc250e5cdd1de783ba9737078e.zip |
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.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 9628b291f960..ea51d827a0bb 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); |